diff --git a/rs/cli/src/commands/hostos/rollout_from_node_group.rs b/rs/cli/src/commands/hostos/rollout_from_node_group.rs
index 30cbc2627..c680c08cd 100644
--- a/rs/cli/src/commands/hostos/rollout_from_node_group.rs
+++ b/rs/cli/src/commands/hostos/rollout_from_node_group.rs
@@ -1,5 +1,3 @@
-use std::str::FromStr;
-
 use clap::{Args, ValueEnum};
 
 use crate::{
@@ -74,9 +72,10 @@ pub struct RolloutFromNodeGroup {
     #[clap(
         long,
         help = r#"How many nodes in the group to update with the version specified
-supported values are absolute numbers (10) or percentage (10%)"#
+supported values are absolute numbers (10) or percentage (10%)"#,
+        default_value = "100%"
     )]
-    pub nodes_in_group: String,
+    pub nodes_in_group: NumberOfNodes,
 
     #[clap(flatten)]
     pub submission_parameters: SubmissionParameters,
@@ -88,7 +87,7 @@ impl ExecutableCommand for RolloutFromNodeGroup {
     }
 
     async fn execute(&self, ctx: crate::ctx::DreContext) -> anyhow::Result<()> {
-        let update_group = NodeGroupUpdate::new(self.assignment, self.owner, NumberOfNodes::from_str(&self.nodes_in_group)?);
+        let update_group = NodeGroupUpdate::new(self.assignment, self.owner, self.nodes_in_group);
         let runner = ctx.runner().await?;
 
         let (nodes_to_update, summary) = match runner
diff --git a/rs/cli/src/commands/propose.rs b/rs/cli/src/commands/propose.rs
index c5fed2386..bb48c90c1 100644
--- a/rs/cli/src/commands/propose.rs
+++ b/rs/cli/src/commands/propose.rs
@@ -1,6 +1,7 @@
 use clap::{error::ErrorKind, Args};
 
 use crate::auth::AuthRequirement;
+use crate::confirm::DryRunType;
 use crate::exe::args::GlobalArgs;
 use crate::exe::ExecutableCommand;
 use crate::{
@@ -49,7 +50,7 @@ impl ExecutableCommand for Propose {
         // This automatically bypasses interactive prompts, as they are unnecessary and unexpected when displaying help.
         let mut submission_params = self.submission_parameters.clone();
         if args.contains(&String::from("--help")) {
-            submission_params.confirmation_mode.dry_run = true;
+            submission_params.confirmation_mode.dry_run = DryRunType::HumanReadable;
         }
 
         Submitter::from(&submission_params)
diff --git a/rs/cli/src/commands/update_default_subnets.rs b/rs/cli/src/commands/update_default_subnets.rs
index 202787bf1..6d8b632c0 100644
--- a/rs/cli/src/commands/update_default_subnets.rs
+++ b/rs/cli/src/commands/update_default_subnets.rs
@@ -137,7 +137,7 @@ impl ExecutableCommand for UpdateDefaultSubnets {
             .collect();
 
         if new_authorized == default_subnets {
-            println!("There are no diffs. Skipping proposal creation.");
+            info!("There are no diffs. Skipping proposal creation.");
             return Ok(());
         }
 
diff --git a/rs/cli/src/commands/vote.rs b/rs/cli/src/commands/vote.rs
index ddba7d3a6..0302accd9 100644
--- a/rs/cli/src/commands/vote.rs
+++ b/rs/cli/src/commands/vote.rs
@@ -9,6 +9,7 @@ use log::info;
 use spinners::{Spinner, Spinners};
 
 use crate::auth::AuthRequirement;
+use crate::confirm::DryRunFormat;
 use crate::exe::{args::GlobalArgs, ExecutableCommand};
 use crate::{
     confirm::{ConfirmationModeOptions, HowToProceed},
@@ -119,7 +120,10 @@ impl ExecutableCommand for Vote {
                                     }
                                 }
                             }
-                            HowToProceed::DryRun => info!("Would have voted for proposal {}", prop_id),
+                            HowToProceed::DryRun(format) => match format {
+                                DryRunFormat::HumanReadable => info!("Would have voted for proposal {}", prop_id),
+                                DryRunFormat::Json => println!("{}", prop_id),
+                            },
                         }
                         voted_proposals.insert(prop_id);
                     }
diff --git a/rs/cli/src/confirm.rs b/rs/cli/src/confirm.rs
index 25ac11273..d9bed9582 100644
--- a/rs/cli/src/confirm.rs
+++ b/rs/cli/src/confirm.rs
@@ -1,10 +1,18 @@
-use clap::Args as ClapArgs;
+use std::str::FromStr;
+
+use clap::{Args as ClapArgs, Parser};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum DryRunFormat {
+    HumanReadable,
+    Json,
+}
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum HowToProceed {
     Confirm,
     Unconditional,
-    DryRun,
+    DryRun(DryRunFormat),
     #[allow(dead_code)]
     UnitTests, // Necessary for unit tests, otherwise confirmation is requested.
                // Generally this is hit when DreContext (created by get_mocked_ctx) has
@@ -12,9 +20,31 @@ pub enum HowToProceed {
                // The net effect is that both the dry run and the final command are run.
 }
 
-#[derive(ClapArgs, Debug, Clone)]
+#[derive(Debug, Clone, Parser)]
+pub(crate) enum DryRunType {
+    NoDryRun,
+    HumanReadable,
+    Json,
+}
+
+impl FromStr for DryRunType {
+    type Err = clap::Error;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "no" => Ok(DryRunType::NoDryRun),
+            "yes" => Ok(DryRunType::HumanReadable),
+            "json" => Ok(DryRunType::Json),
+            _ => {
+                let mut cmd = clap::Command::new("dre");
+                Err(cmd.error(clap::error::ErrorKind::InvalidValue, format!("invalid value {} for --dry-run", s)))
+            }
+        }
+    }
+}
 
 /// Options for commands that may require confirmation.
+#[derive(ClapArgs, Debug, Clone)]
 pub struct ConfirmationModeOptions {
     /// To skip the confirmation prompt
     #[clap(
@@ -28,25 +58,29 @@ pub struct ConfirmationModeOptions {
     )]
     yes: bool,
 
-    #[clap(long, aliases = [ "dry-run", "dryrun", "simulate", "no"], env = "DRY_RUN", global = true, conflicts_with = "yes", help = r#"Dry-run, or simulate operation. If specified will not make any changes; instead, it will show what would be done or submitted."#,help_heading = "Options on how to proceed")]
-    pub(crate) dry_run: bool,
+    #[clap(long, aliases = [ "dry-run", "dryrun", "simulate", "no"], env = "DRY_RUN", global = true, conflicts_with = "yes", help = r#"Dry-run, or simulate operation. If specified will not make any changes; instead, it will show what would be done or submitted.  If specified as --dry-run=json, it will print machine-readable JSON to standard output."#, help_heading = "Options on how to proceed", num_args = 0..=1, default_value="no", default_missing_value="yes")]
+    pub(crate) dry_run: DryRunType,
 }
 
 #[cfg(test)]
 impl ConfirmationModeOptions {
     /// Return an option set for unit tests, not instantiable via command line due to conflict.
     pub fn for_unit_tests() -> Self {
-        ConfirmationModeOptions { yes: true, dry_run: true }
+        ConfirmationModeOptions {
+            yes: true,
+            dry_run: DryRunType::HumanReadable,
+        }
     }
 }
 
 impl From<&ConfirmationModeOptions> for HowToProceed {
     fn from(o: &ConfirmationModeOptions) -> Self {
-        match (o.dry_run, o.yes) {
-            (false, true) => Self::Unconditional,
-            (true, false) => Self::DryRun,
-            (false, false) => Self::Confirm,
-            (true, true) => Self::UnitTests, // This variant cannot be instantiated via the command line.
+        match (&o.dry_run, o.yes) {
+            (DryRunType::NoDryRun, true) => Self::Unconditional,
+            (DryRunType::NoDryRun, false) => Self::Confirm,
+            (DryRunType::HumanReadable, false) => Self::DryRun(DryRunFormat::HumanReadable),
+            (DryRunType::Json, false) => Self::DryRun(DryRunFormat::Json),
+            (_, true) => Self::UnitTests, // These variants cannot be instantiated via the command line.
         }
     }
 }
diff --git a/rs/cli/src/forum/impls.rs b/rs/cli/src/forum/impls.rs
index 5e2ec764f..5cce448e9 100644
--- a/rs/cli/src/forum/impls.rs
+++ b/rs/cli/src/forum/impls.rs
@@ -178,7 +178,7 @@ impl Discourse {
             warn!("While creating a new post in topic {}, Discourse returned an error: {:?}", topic_url, e);
         }
         warn!("Please create a post in topic {} with the following content", topic_url);
-        println!("{}", body);
+        eprintln!("{}", body);
         let forum_post_link = dialoguer::Input::<String>::new()
             .with_prompt("Forum post link")
             .allow_empty(false)
diff --git a/rs/cli/src/governance.rs b/rs/cli/src/governance.rs
index b6a45aeda..09cbe1686 100644
--- a/rs/cli/src/governance.rs
+++ b/rs/cli/src/governance.rs
@@ -2,6 +2,7 @@ use futures::future::BoxFuture;
 use ic_canisters::governance::GovernanceCanisterWrapper;
 use ic_nns_common::pb::v1::NeuronId;
 use ic_nns_governance_api::MakeProposalRequest;
+use serde_json::json;
 use url::Url;
 
 use crate::proposal_executors::{ProposableViaGovernanceCanister, ProposalExecution, ProposalResponseWithId};
@@ -32,14 +33,22 @@ impl GovernanceCanisterProposalExecutor {
     pub fn simulate<'c, 'd, W: ProposableViaGovernanceCanister + 'c>(
         &'d self,
         cmd: &'c W,
+        machine_readable: bool,
         forum_post_link_description: Option<String>,
     ) -> BoxFuture<'c, anyhow::Result<()>>
     where
         'd: 'c,
     {
         Box::pin(async move {
-            println!("Proposal that would be submitted:\n{:#?}", cmd);
-            println!("Forum post link: {}", forum_post_link_description.unwrap_or("None".to_string()));
+            match machine_readable {
+                false => {
+                    println!("Proposal that would be submitted:\n{:#?}", cmd);
+                    println!("Forum post link: {}", forum_post_link_description.unwrap_or("None".to_string()));
+                }
+                true => {
+                    println!("{}", json!(cmd));
+                }
+            }
             Ok(())
         })
     }
@@ -85,8 +94,12 @@ impl<T> ProposalExecution for ProposalExecutionViaGovernanceCanister<T>
 where
     T: ProposableViaGovernanceCanister<ProposalResult = ProposalResponseWithId>,
 {
-    fn simulate(&self, forum_post_link_description: Option<String>) -> BoxFuture<'_, anyhow::Result<()>> {
-        Box::pin(async { self.executor.simulate(&self.proposal, forum_post_link_description).await })
+    fn simulate(&self, machine_readable: bool, forum_post_link_description: Option<String>) -> BoxFuture<'_, anyhow::Result<()>> {
+        Box::pin(async move {
+            self.executor
+                .simulate(&self.proposal, machine_readable, forum_post_link_description)
+                .await
+        })
     }
 
     fn submit<'a, 'b>(&'a self, forum_post_link: Option<Url>) -> BoxFuture<'b, anyhow::Result<ProposalResponseWithId>>
diff --git a/rs/cli/src/ic_admin.rs b/rs/cli/src/ic_admin.rs
index 340edb04a..f27db2e92 100644
--- a/rs/cli/src/ic_admin.rs
+++ b/rs/cli/src/ic_admin.rs
@@ -32,7 +32,12 @@ pub trait IcAdmin: Send + Sync + Debug {
     fn ic_admin_path(&self) -> Option<String>;
 
     /// Runs the proposal in simulation mode (--dry-run).  Prints out the result.
-    fn simulate_proposal(&self, cmd: Vec<String>, forum_post_link_description: Option<String>) -> BoxFuture<'_, anyhow::Result<()>>;
+    fn simulate_proposal(
+        &self,
+        cmd: Vec<String>,
+        machine_readable: bool,
+        forum_post_link_description: Option<String>,
+    ) -> BoxFuture<'_, anyhow::Result<()>>;
 
     /// Runs the proposal in forrealz mode.  Result is returned and logged at debug level.
     fn submit_proposal<'a, 'b>(&'a self, cmd: Vec<String>, forum_post_link: Option<Url>) -> BoxFuture<'b, anyhow::Result<String>>
@@ -148,7 +153,12 @@ impl IcAdmin for IcAdminImpl {
         })
     }
 
-    fn simulate_proposal(&self, cmd: Vec<String>, forum_post_link_description: Option<String>) -> BoxFuture<'_, anyhow::Result<()>> {
+    fn simulate_proposal(
+        &self,
+        cmd: Vec<String>,
+        machine_readable: bool,
+        forum_post_link_description: Option<String>,
+    ) -> BoxFuture<'_, anyhow::Result<()>> {
         Box::pin(async move {
             debug!("Simulating proposal {:?}.", cmd);
 
@@ -168,11 +178,15 @@ impl IcAdmin for IcAdminImpl {
             if !args.contains(&String::from("--dry-run")) {
                 args.push("--dry-run".into())
             };
+            // When we want to simulate as JSON.
+            if machine_readable {
+                args.push("--json".into())
+            }
 
             self.run(args.as_slice(), true).await.map(|r| r.trim().to_string())?;
 
             // Add the forum post link description as a string after the ic-admin command.
-            if forum_post_link_description.is_some() && !is_forum_post_link_description_url {
+            if forum_post_link_description.is_some() && !is_forum_post_link_description_url && !machine_readable {
                 println!("Forum post link: {}", forum_post_link_description.unwrap());
             }
 
@@ -546,6 +560,7 @@ impl IcAdminProposalExecutor {
     pub fn simulate<'c, 'd, T: RunnableViaIcAdmin + 'c>(
         &'d self,
         cmd: &'c T,
+        machine_readable: bool,
         forum_post_link_description: Option<String>,
     ) -> BoxFuture<'c, anyhow::Result<()>>
     where
@@ -553,7 +568,9 @@ impl IcAdminProposalExecutor {
     {
         Box::pin(async move {
             let propose_command = cmd.to_ic_admin_arguments()?;
-            self.ic_admin.simulate_proposal(propose_command, forum_post_link_description).await?;
+            self.ic_admin
+                .simulate_proposal(propose_command, machine_readable, forum_post_link_description)
+                .await?;
             Ok(())
         })
     }
@@ -587,8 +604,12 @@ where
     T: RunnableViaIcAdmin<Output = ProposalResponseWithId>,
     T: ProducesProposalResult<ProposalResult = ProposalResponseWithId>,
 {
-    fn simulate(&self, forum_post_link_description: Option<String>) -> BoxFuture<'_, anyhow::Result<()>> {
-        Box::pin(async { self.executor.simulate(&self.proposal, forum_post_link_description).await })
+    fn simulate(&self, machine_readable: bool, forum_post_link_description: Option<String>) -> BoxFuture<'_, anyhow::Result<()>> {
+        Box::pin(async move {
+            self.executor
+                .simulate(&self.proposal, machine_readable, forum_post_link_description)
+                .await
+        })
     }
 
     fn submit<'a, 'b>(&'a self, forum_post_link: Option<Url>) -> BoxFuture<'b, anyhow::Result<ProposalResponseWithId>>
diff --git a/rs/cli/src/operations/hostos_rollout.rs b/rs/cli/src/operations/hostos_rollout.rs
index d77eb7c48..4c8981bb8 100644
--- a/rs/cli/src/operations/hostos_rollout.rs
+++ b/rs/cli/src/operations/hostos_rollout.rs
@@ -58,21 +58,38 @@ impl std::fmt::Display for NodeGroup {
 }
 #[derive(Copy, Clone, Debug, Ord, Eq, PartialEq, PartialOrd)]
 pub enum NumberOfNodes {
-    Percentage(i32),
-    Absolute(i32),
+    Percentage(u32),
+    Absolute(u32),
 }
 impl FromStr for NumberOfNodes {
-    type Err = anyhow::Error;
+    type Err = clap::Error;
     fn from_str(input: &str) -> Result<Self, Self::Err> {
         if input.ends_with('%') {
-            let percentage = i32::from_str(input.trim_end_matches('%'))?;
+            let percentage = match u32::from_str(input.trim_end_matches('%')) {
+                Ok(p) => p,
+                Err(e) => {
+                    return Err(
+                        clap::Command::new("dre").error(clap::error::ErrorKind::InvalidValue, format!("while parsing --nodes-in-group: {}", e))
+                    )
+                }
+            };
             if (0..=100).contains(&percentage) {
                 Ok(NumberOfNodes::Percentage(percentage))
             } else {
-                Err(anyhow!("Percentage must be between 0 and 100"))
+                Err(clap::Command::new("dre").error(
+                    clap::error::ErrorKind::InvalidValue,
+                    "while parsing --nodes-in-group: percentage must be between 0 and 100",
+                ))
             }
         } else {
-            Ok(NumberOfNodes::Absolute(i32::from_str(input)?))
+            Ok(NumberOfNodes::Absolute(match u32::from_str(input) {
+                Ok(v) => v,
+                Err(e) => {
+                    return Err(
+                        clap::Command::new("dre").error(clap::error::ErrorKind::InvalidValue, format!("while parsing --nodes-in-group: {}", e))
+                    )
+                }
+            }))
         }
     }
 }
@@ -95,13 +112,13 @@ impl std::fmt::Display for NumberOfNodes {
 #[derive(Copy, Clone, Debug, Ord, Eq, PartialEq, PartialOrd)]
 pub struct NodeGroupUpdate {
     pub node_group: NodeGroup,
-    pub maybe_number_nodes: Option<NumberOfNodes>,
+    pub number_nodes: NumberOfNodes,
 }
 impl NodeGroupUpdate {
     pub fn new(assignment: Option<NodeAssignment>, owner: Option<NodeOwner>, nodes_per_subnet: NumberOfNodes) -> Self {
         NodeGroupUpdate {
             node_group: NodeGroup::new(assignment.unwrap_or_default(), owner.unwrap_or_default()),
-            maybe_number_nodes: Some(nodes_per_subnet),
+            number_nodes: nodes_per_subnet,
         }
     }
 
@@ -111,11 +128,11 @@ impl NodeGroupUpdate {
                 assignment,
                 owner: self.node_group.owner,
             },
-            maybe_number_nodes: self.maybe_number_nodes,
+            number_nodes: self.number_nodes,
         }
     }
     pub fn nodes_to_take(&self, group_size: usize) -> usize {
-        match self.maybe_number_nodes.unwrap_or_default() {
+        match self.number_nodes {
             NumberOfNodes::Percentage(percent_to_update) => (group_size as f32 * percent_to_update as f32 / 100.0).floor() as usize,
             NumberOfNodes::Absolute(number_nodes) => number_nodes as usize,
         }
@@ -378,7 +395,7 @@ impl HostosRollout {
                     }
                 })
                 .count(),
-            update_group.maybe_number_nodes.unwrap_or_default(),
+            update_group.number_nodes,
             update_group.node_group.owner,
             update_group.node_group.assignment
         );
@@ -393,8 +410,9 @@ impl HostosRollout {
                 {
                     CandidatesSelection::Ok(candidates_unassigned) => {
                         let nodes_to_take = update_group.nodes_to_take(unassigned_nodes.len());
-                        let nodes_to_update = candidates_unassigned.into_iter().take(nodes_to_take).collect::<Vec<_>>();
+                        let nodes_to_update = candidates_unassigned.clone().into_iter().take(nodes_to_take).collect::<Vec<_>>();
                         info!("{} candidate nodes selected for: {}", nodes_to_update.len(), update_group.node_group);
+
                         Ok(HostosRolloutResponse::Ok(nodes_to_update, None))
                     }
                     CandidatesSelection::None(reason) => {
@@ -532,6 +550,7 @@ pub mod test {
     use ic_management_backend::health::MockHealthStatusQuerier;
     use ic_management_backend::proposal::ProposalAgentImpl;
     use ic_management_types::{Network, Node, Operator, Provider, Subnet};
+    use ic_protobuf::registry::node::v1::NodeRewardType;
     use std::collections::BTreeMap;
     use std::sync::OnceLock;
 
@@ -596,7 +615,7 @@ pub mod test {
                 open_proposals.clone(),
                 NodeGroupUpdate {
                     node_group: NodeGroup::new(Assigned, Others),
-                    maybe_number_nodes: None,
+                    number_nodes: NumberOfNodes::Percentage(100),
                 },
             )
             .await;
@@ -635,7 +654,7 @@ pub mod test {
                 open_proposals.clone(),
                 NodeGroupUpdate {
                     node_group: NodeGroup::new(Assigned, Others),
-                    maybe_number_nodes: None,
+                    number_nodes: NumberOfNodes::Percentage(100),
                 },
             )
             .await
@@ -688,6 +707,7 @@ pub mod test {
         for i in start_at_number..start_at_number + num_nodes {
             let node = Node {
                 principal: PrincipalId::new_node_test_id(i),
+                node_reward_type: Some(NodeRewardType::Type3),
                 ip_addr: None,
                 operator: Operator {
                     principal: PrincipalId::new_node_test_id(i),
@@ -700,6 +720,7 @@ pub mod test {
                     datacenter: None,
                     rewardable_nodes: BTreeMap::new(),
                     ipv6: "".to_string(),
+                    max_rewardable_nodes: BTreeMap::new(),
                 },
                 cached_features: OnceLock::new(),
                 hostname: None,
diff --git a/rs/cli/src/proposal_executors.rs b/rs/cli/src/proposal_executors.rs
index ee306f25f..54c3ae291 100644
--- a/rs/cli/src/proposal_executors.rs
+++ b/rs/cli/src/proposal_executors.rs
@@ -98,7 +98,7 @@ pub trait ProducesProposalResult {
 /// Represents anything that can be turned into a proposal request
 /// suitable to be made through the GovernanceCanisterWrapper, and
 /// also has the ability to deserialize to a ProposalResponseWithId.
-pub trait ProposableViaGovernanceCanister: Debug + Send + Sync + Clone + Into<MakeProposalRequest> {
+pub trait ProposableViaGovernanceCanister: Debug + Send + Sync + Clone + Into<MakeProposalRequest> + serde::Serialize {
     type ProposalResult: TryFrom<u64> + TryInto<ProposalResponseWithId>;
 }
 
@@ -112,7 +112,7 @@ impl ProposableViaGovernanceCanister for MakeProposalRequest {
 /// of a proposal (any object that implements either RunnableViaIcAdmin or
 /// ProposableViaGovernanceCanister, and produces a ProposalResponseWithId).
 pub trait ProposalExecution: Send + Sync {
-    fn simulate(&self, forum_post_link_description: Option<String>) -> BoxFuture<'_, anyhow::Result<()>>;
+    fn simulate(&self, machine_readable: bool, forum_post_link_description: Option<String>) -> BoxFuture<'_, anyhow::Result<()>>;
 
     /// Runs the proposal in forrealz mode.  Result is returned and logged at debug level.
     fn submit<'a, 'b>(&'a self, forum_post_link: Option<Url>) -> BoxFuture<'b, anyhow::Result<ProposalResponseWithId>>
diff --git a/rs/cli/src/runner.rs b/rs/cli/src/runner.rs
index e5f89c303..b4665ec39 100644
--- a/rs/cli/src/runner.rs
+++ b/rs/cli/src/runner.rs
@@ -33,6 +33,7 @@ use ic_management_types::TopologyChangePayload;
 use ic_types::PrincipalId;
 use indexmap::{IndexMap, IndexSet};
 use itertools::Itertools;
+use log::error;
 use log::info;
 use log::warn;
 
@@ -157,10 +158,10 @@ impl Runner {
 
         if self.verbose {
             if let Some(run_log) = &subnet_creation_data.run_log {
-                println!("{}\n", run_log.join("\n"));
+                info!("{}\n", run_log.join("\n"));
             }
         }
-        println!("{}", subnet_creation_data);
+        info!("{}", subnet_creation_data);
         let replica_version = replica_version.unwrap_or(
             self.registry
                 .nns_replica_version()
@@ -192,7 +193,7 @@ impl Runner {
     pub async fn propose_subnet_change(&self, change: &SubnetChangeResponse) -> anyhow::Result<Option<IcAdminProposal>> {
         if self.verbose {
             if let Some(run_log) = &change.run_log {
-                println!("{}\n", run_log.join("\n"));
+                info!("{}\n", run_log.join("\n"));
             }
         }
 
@@ -411,7 +412,7 @@ impl Runner {
             HostosRolloutResponse::None(reason) => {
                 reason
                     .iter()
-                    .for_each(|(group, reason)| println!("No nodes to update in group: {} because: {}", group, reason));
+                    .for_each(|(group, reason)| error!("No nodes to update in group: {} because: {}", group, reason));
                 Ok(None)
             }
         }
@@ -424,8 +425,8 @@ impl Runner {
             .iter()
             .map(|p| p.to_string().split('-').next().unwrap().to_string())
             .collect::<Vec<_>>();
-        println!("Will submit proposal to update the following nodes: {:?}", nodes_short);
-        println!("You will be able to follow the upgrade progress at https://grafana.mainnet.dfinity.network/explore?orgId=1&left=%7B%22datasource%22:%22PE62C54679EC3C073%22,%22queries%22:%5B%7B%22refId%22:%22A%22,%22datasource%22:%7B%22type%22:%22prometheus%22,%22uid%22:%22PE62C54679EC3C073%22%7D,%22editorMode%22:%22code%22,%22expr%22:%22hostos_version%7Bic_node%3D~%5C%22{}%5C%22%7D%5Cn%22,%22legendFormat%22:%22__auto%22,%22range%22:true,%22instant%22:true%7D%5D,%22range%22:%7B%22from%22:%22now-1h%22,%22to%22:%22now%22%7D%7D", nodes_short.iter().map(|n| n.to_string() + ".%2B").join("%7C"));
+        info!("Will submit proposal to update the following nodes: {:?}", nodes_short);
+        info!("You will be able to follow the upgrade progress at https://grafana.mainnet.dfinity.network/explore?orgId=1&left=%7B%22datasource%22:%22PE62C54679EC3C073%22,%22queries%22:%5B%7B%22refId%22:%22A%22,%22datasource%22:%7B%22type%22:%22prometheus%22,%22uid%22:%22PE62C54679EC3C073%22%7D,%22editorMode%22:%22code%22,%22expr%22:%22hostos_version%7Bic_node%3D~%5C%22{}%5C%22%7D%5Cn%22,%22legendFormat%22:%22__auto%22,%22range%22:true,%22instant%22:true%7D%5D,%22range%22:%7B%22from%22:%22now-1h%22,%22to%22:%22now%22%7D%7D", nodes_short.iter().map(|n| n.to_string() + ".%2B").join("%7C"));
 
         Ok(IcAdminProposal::new(
             IcAdminProposalCommand::DeployHostosToSomeNodes {
@@ -473,7 +474,7 @@ impl Runner {
             row.add_cell(nr.reason.message());
             table.add_row(row);
         }
-        println!("{}", table);
+        info!("{}", table);
 
         Ok(IcAdminProposal::new(
             ic_admin::IcAdminProposalCommand::RemoveNodes {
@@ -541,7 +542,7 @@ impl Runner {
                 .run_membership_change(change, replace_proposal_options(change).await?)
                 .await
                 .map_err(|e| {
-                    println!("{}", e);
+                    error!("{}", e);
                     errors.push(e);
                 });
             changes.push(current)
@@ -904,7 +905,7 @@ impl Runner {
             removed_nodes: removed_nodes.clone(),
             ..Default::default()
         };
-        println!("{}", SubnetChangeResponse::new(&subnet_change, &health_of_nodes, summary));
+        info!("{}", SubnetChangeResponse::new(&subnet_change, &health_of_nodes, summary));
         Ok(())
     }
 
diff --git a/rs/cli/src/submitter.rs b/rs/cli/src/submitter.rs
index 39033d792..cd9468dfd 100644
--- a/rs/cli/src/submitter.rs
+++ b/rs/cli/src/submitter.rs
@@ -2,7 +2,7 @@ use clap::Args as ClapArgs;
 use log::warn;
 
 use crate::{
-    confirm::{ConfirmationModeOptions, HowToProceed},
+    confirm::{ConfirmationModeOptions, DryRunFormat, HowToProceed},
     forum::{ForumContext, ForumParameters, ForumPostKind},
     proposal_executors::{ProposalExecution, ProposalResponseWithId},
     util::yesno,
@@ -43,7 +43,10 @@ impl Submitter {
     pub async fn propose(&self, execution: Box<dyn ProposalExecution>, kind: ForumPostKind) -> anyhow::Result<Option<ProposalResponseWithId>> {
         if let HowToProceed::Unconditional = self.mode {
         } else {
-            execution.simulate(self.forum_parameters.forum_post_link_for_simulation()).await?;
+            let machine_readable = matches!(self.mode, HowToProceed::DryRun(DryRunFormat::Json));
+            execution
+                .simulate(machine_readable, self.forum_parameters.forum_post_link_for_simulation())
+                .await?;
         };
 
         if let HowToProceed::Confirm = self.mode {
@@ -53,7 +56,7 @@ impl Submitter {
             }
         }
 
-        if let HowToProceed::DryRun = self.mode {
+        if let HowToProceed::DryRun(_) = self.mode {
             Ok(None)
         } else {
             let forum_post = ForumContext::from(&self.forum_parameters).client()?.forum_post(kind).await?;
diff --git a/rs/cli/src/unit_tests/cordoned_feature_fetcher.rs b/rs/cli/src/unit_tests/cordoned_feature_fetcher.rs
index 2d8a5a28e..511c88f74 100644
--- a/rs/cli/src/unit_tests/cordoned_feature_fetcher.rs
+++ b/rs/cli/src/unit_tests/cordoned_feature_fetcher.rs
@@ -101,7 +101,7 @@ fn cordoned_feature_fetcher_tests() {
     let mut failed_scenarios = vec![];
 
     for scenario in &scenarios {
-        println!("### Starting scenario `{}`", scenario.name);
+        eprintln!("### Starting scenario `{}`", scenario.name);
         let store = Store::new(scenario.offline).unwrap();
 
         match &scenario.cache_contents {
@@ -117,7 +117,7 @@ fn cordoned_feature_fetcher_tests() {
             if let Ok(features) = maybe_cordoned_features {
                 failed_scenarios.push((features, scenario));
             }
-            println!("### Ending scenario `{}`", scenario.name);
+            eprintln!("### Ending scenario `{}`", scenario.name);
             continue;
         }
 
@@ -128,7 +128,7 @@ fn cordoned_feature_fetcher_tests() {
         if !cordoned_features.eq(&cordoned_features_from_cache) {
             failed_scenarios.push((cordoned_features, scenario));
         }
-        println!("### Ending scenario `{}`", scenario.name);
+        eprintln!("### Ending scenario `{}`", scenario.name);
     }
 
     assert!(
diff --git a/rs/cli/src/unit_tests/health_client.rs b/rs/cli/src/unit_tests/health_client.rs
index 8156b4357..71191c99c 100644
--- a/rs/cli/src/unit_tests/health_client.rs
+++ b/rs/cli/src/unit_tests/health_client.rs
@@ -95,7 +95,7 @@ fn health_client_tests() {
 
     let mut failed_scenarios = vec![];
     for scenario in &scenarios {
-        println!("### Starting scenario `{}`", scenario.name);
+        eprintln!("### Starting scenario `{}`", scenario.name);
         let store = Store::new(scenario.offline).unwrap();
         let network = ic_management_types::Network::new_unchecked(scenario.network.clone(), &[]).unwrap();
         let cache_path = store.node_health_file_outer(&network).unwrap();
@@ -111,13 +111,13 @@ fn health_client_tests() {
 
         if scenario.should_succeed != maybe_nodes_info.is_ok() {
             failed_scenarios.push((maybe_nodes_info, scenario));
-            println!("### Ending scenario `{}`", scenario.name);
+            eprintln!("### Ending scenario `{}`", scenario.name);
             continue;
         }
 
         // Scenario should fail but it is expected to fail
         if !scenario.should_succeed {
-            println!("### Ending scenario `{}`", scenario.name);
+            eprintln!("### Ending scenario `{}`", scenario.name);
             continue;
         }
 
@@ -129,6 +129,6 @@ fn health_client_tests() {
             failed_scenarios.push((Ok(nodes_info), scenario));
         }
 
-        println!("### Ending scenario `{}`", scenario.name);
+        eprintln!("### Ending scenario `{}`", scenario.name);
     }
 }
diff --git a/rs/cli/src/unit_tests/node_labels.rs b/rs/cli/src/unit_tests/node_labels.rs
index 9cfe909f7..e15c660bb 100644
--- a/rs/cli/src/unit_tests/node_labels.rs
+++ b/rs/cli/src/unit_tests/node_labels.rs
@@ -121,7 +121,7 @@ fn test_node_labels() {
     let mut failed_scenarios = vec![];
 
     for scenario in &scenarios {
-        println!("### Starting scenario `{}`", scenario.name);
+        eprintln!("### Starting scenario `{}`", scenario.name);
         let network = Network::new_unchecked(scenario.network.clone(), &[]).unwrap();
         let store = Store::new(scenario.offline).unwrap();
         let labels_path = store.guest_labels_cache_path_outer(&network).unwrap();
@@ -141,7 +141,7 @@ fn test_node_labels() {
             if let Ok(labels) = maybe_labels {
                 failed_scenarios.push((labels, scenario));
             }
-            println!("### Ending scenario `{}`", scenario.name);
+            eprintln!("### Ending scenario `{}`", scenario.name);
             continue;
         }
 
@@ -151,7 +151,7 @@ fn test_node_labels() {
         if !labels.eq(&labels_from_cache) {
             failed_scenarios.push((labels, scenario));
         }
-        println!("### Ending scenario `{}`", scenario.name);
+        eprintln!("### Ending scenario `{}`", scenario.name);
     }
 
     assert!(
diff --git a/rs/cli/src/unit_tests/update_unassigned_nodes.rs b/rs/cli/src/unit_tests/update_unassigned_nodes.rs
index 8c185b9da..17c24d0ef 100644
--- a/rs/cli/src/unit_tests/update_unassigned_nodes.rs
+++ b/rs/cli/src/unit_tests/update_unassigned_nodes.rs
@@ -122,7 +122,7 @@ async fn should_skip_update_same_version_nns_provided() {
 async fn should_update_unassigned_nodes() {
     let mut ic_admin = MockIcAdmin::new();
     // Should be called since versions differ
-    ic_admin.expect_simulate_proposal().once().returning(|_, _| Box::pin(async { Ok(()) }));
+    ic_admin.expect_simulate_proposal().once().returning(|_, _, _| Box::pin(async { Ok(()) }));
     ic_admin
         .expect_submit_proposal()
         .once()
diff --git a/rs/cli/src/unit_tests/version.rs b/rs/cli/src/unit_tests/version.rs
index 084183519..43bfe4ff6 100644
--- a/rs/cli/src/unit_tests/version.rs
+++ b/rs/cli/src/unit_tests/version.rs
@@ -33,7 +33,7 @@ async fn guest_os_elect_version_tests() {
     let captured_cmd_clone = captured_cmd.clone();
 
     let mut ic_admin = MockIcAdmin::new();
-    ic_admin.expect_simulate_proposal().returning(|_, _| Box::pin(async { Ok(()) }));
+    ic_admin.expect_simulate_proposal().returning(|_, _, _| Box::pin(async { Ok(()) }));
     let captured_cmd_clone = captured_cmd_clone.clone();
     ic_admin.expect_submit_proposal().returning(move |cmd, _forum_post| {
         *captured_cmd_clone.write().unwrap() = Some(cmd.clone());