diff --git a/src/trace/implementations/merge_batcher.rs b/src/trace/implementations/merge_batcher.rs
index 1bae0ef2a..63d724979 100644
--- a/src/trace/implementations/merge_batcher.rs
+++ b/src/trace/implementations/merge_batcher.rs
@@ -16,10 +16,10 @@ use crate::trace::{Batcher, Builder};
 use crate::Data;
 
 /// Creates batches from unordered tuples.
-pub struct MergeBatcher<Input, C, M, T>
+pub struct MergeBatcher<Input, C, M>
 where
-    C: ContainerBuilder<Container=M::Chunk> + Default,
-    M: Merger<Time = T>,
+    C: ContainerBuilder<Container=M::Chunk>,
+    M: Merger,
 {
     /// each power-of-two length list of allocations.
     /// Do not push/pop directly but use the corresponding functions
@@ -36,20 +36,20 @@ where
     /// Timely operator ID.
     operator_id: usize,
     /// Current lower frontier, we sealed up to here.
-    lower: Antichain<T>,
+    lower: Antichain<M::Time>,
     /// The lower-bound frontier of the data, after the last call to seal.
-    frontier: Antichain<T>,
+    frontier: Antichain<M::Time>,
     _marker: PhantomData<Input>,
 }
 
-impl<Input, C, M, T> Batcher for MergeBatcher<Input, C, M, T>
+impl<Input, C, M> Batcher for MergeBatcher<Input, C, M>
 where
     C: ContainerBuilder<Container=M::Chunk> + Default + for<'a> PushInto<&'a mut Input>,
-    M: Merger<Time = T>,
-    T: Timestamp,
+    M: Merger,
+    M::Time: Timestamp,
 {
     type Input = Input;
-    type Time = T;
+    type Time = M::Time;
     type Output = M::Chunk;
 
     fn new(logger: Option<Logger<DifferentialEvent, WorkerIdentifier>>, operator_id: usize) -> Self {
@@ -61,7 +61,7 @@ where
             chains: Vec::new(),
             stash: Vec::new(),
             frontier: Antichain::new(),
-            lower: Antichain::from_elem(T::minimum()),
+            lower: Antichain::from_elem(M::Time::minimum()),
             _marker: PhantomData,
         }
     }
@@ -80,7 +80,7 @@ where
     // in `upper`. All updates must have time greater or equal to the previously used `upper`,
     // which we call `lower`, by assumption that after sealing a batcher we receive no more
     // updates with times not greater or equal to `upper`.
-    fn seal<B: Builder<Input = Self::Output, Time = Self::Time>>(&mut self, upper: Antichain<T>) -> B::Output {
+    fn seal<B: Builder<Input = Self::Output, Time = Self::Time>>(&mut self, upper: Antichain<M::Time>) -> B::Output {
         // Finish
         while let Some(chunk) = self.chunker.finish() {
             let chunk = std::mem::take(chunk);
@@ -109,22 +109,22 @@ where
 
         self.stash.clear();
 
-        let seal = B::seal(&mut readied, self.lower.borrow(), upper.borrow(), Antichain::from_elem(T::minimum()).borrow());
+        let seal = B::seal(&mut readied, self.lower.borrow(), upper.borrow(), Antichain::from_elem(M::Time::minimum()).borrow());
         self.lower = upper;
         seal
     }
 
     /// The frontier of elements remaining after the most recent call to `self.seal`.
     #[inline]
-    fn frontier(&mut self) -> AntichainRef<T> {
+    fn frontier(&mut self) -> AntichainRef<M::Time> {
         self.frontier.borrow()
     }
 }
 
-impl<Input, C, M, T> MergeBatcher<Input, C, M, T>
+impl<Input, C, M> MergeBatcher<Input, C, M>
 where
     C: ContainerBuilder<Container=M::Chunk> + Default,
-    M: Merger<Time = T>,
+    M: Merger,
 {
     /// Insert a chain and maintain chain properties: Chains are geometrically sized and ordered
     /// by decreasing length.
@@ -189,10 +189,10 @@ where
     }
 }
 
-impl<Input, C, M, T> Drop for MergeBatcher<Input, C, M, T>
+impl<Input, C, M> Drop for MergeBatcher<Input, C, M>
 where
     C: ContainerBuilder<Container=M::Chunk> + Default,
-    M: Merger<Time = T>,
+    M: Merger,
 {
     fn drop(&mut self) {
         // Cleanup chain to retract accounting information.
diff --git a/src/trace/implementations/ord_neu.rs b/src/trace/implementations/ord_neu.rs
index 8228294b1..26270c004 100644
--- a/src/trace/implementations/ord_neu.rs
+++ b/src/trace/implementations/ord_neu.rs
@@ -17,7 +17,7 @@ use crate::trace::implementations::chunker::{ColumnationChunker, ContainerChunke
 use crate::trace::implementations::spine_fueled::Spine;
 use crate::trace::implementations::merge_batcher::{MergeBatcher, VecMerger};
 use crate::trace::implementations::merge_batcher_col::ColumnationMerger;
-use crate::trace::implementations::merge_batcher_flat::{FlatcontainerMerger, MergerChunk};
+use crate::trace::implementations::merge_batcher_flat::FlatcontainerMerger;
 use crate::trace::rc_blanket_impls::RcBuilder;
 
 use super::{Update, Layout, Vector, TStack, Preferred, FlatLayout};
@@ -28,7 +28,7 @@ pub use self::key_batch::{OrdKeyBatch, OrdKeyBuilder};
 /// A trace implementation using a spine of ordered lists.
 pub type OrdValSpine<K, V, T, R> = Spine<Rc<OrdValBatch<Vector<((K,V),T,R)>>>>;
 /// A batcher using ordered lists.
-pub type OrdValBatcher<K, V, T, R> = MergeBatcher<Vec<((K,V),T,R)>, VecChunker<((K,V),T,R)>, VecMerger<((K, V), T, R)>, T>;
+pub type OrdValBatcher<K, V, T, R> = MergeBatcher<Vec<((K,V),T,R)>, VecChunker<((K,V),T,R)>, VecMerger<((K, V), T, R)>>;
 /// A builder using ordered lists.
 pub type RcOrdValBuilder<K, V, T, R> = RcBuilder<OrdValBuilder<Vector<((K,V),T,R)>, Vec<((K,V),T,R)>>>;
 
@@ -38,14 +38,14 @@ pub type RcOrdValBuilder<K, V, T, R> = RcBuilder<OrdValBuilder<Vector<((K,V),T,R
 /// A trace implementation backed by columnar storage.
 pub type ColValSpine<K, V, T, R> = Spine<Rc<OrdValBatch<TStack<((K,V),T,R)>>>>;
 /// A batcher for columnar storage.
-pub type ColValBatcher<K, V, T, R> = MergeBatcher<Vec<((K,V),T,R)>, ColumnationChunker<((K,V),T,R)>, ColumnationMerger<((K,V),T,R)>, T>;
+pub type ColValBatcher<K, V, T, R> = MergeBatcher<Vec<((K,V),T,R)>, ColumnationChunker<((K,V),T,R)>, ColumnationMerger<((K,V),T,R)>>;
 /// A builder for columnar storage.
 pub type ColValBuilder<K, V, T, R> = RcBuilder<OrdValBuilder<TStack<((K,V),T,R)>, TimelyStack<((K,V),T,R)>>>;
 
 /// A trace implementation backed by flatcontainer storage.
 pub type FlatValSpine<L> = Spine<Rc<OrdValBatch<L>>>;
 /// A batcher for flatcontainer storage.
-pub type FlatValBatcher<R, C> = MergeBatcher<C, ContainerChunker<FlatStack<R>>, FlatcontainerMerger<R>, <R as MergerChunk>::TimeOwned>;
+pub type FlatValBatcher<R, C> = MergeBatcher<C, ContainerChunker<FlatStack<R>>, FlatcontainerMerger<R>>;
 /// A builder for flatcontainer storage.
 pub type FlatValBuilder<L, R> = RcBuilder<OrdValBuilder<L, FlatStack<R>>>;
 
@@ -63,7 +63,7 @@ pub type FlatValBuilderDefault<K, V, T, R> = FlatValBuilder<FlatLayout<<K as Reg
 /// A trace implementation using a spine of ordered lists.
 pub type OrdKeySpine<K, T, R> = Spine<Rc<OrdKeyBatch<Vector<((K,()),T,R)>>>>;
 /// A batcher for ordered lists.
-pub type OrdKeyBatcher<K, T, R> = MergeBatcher<Vec<((K,()),T,R)>, VecChunker<((K,()),T,R)>, VecMerger<((K, ()), T, R)>, T>;
+pub type OrdKeyBatcher<K, T, R> = MergeBatcher<Vec<((K,()),T,R)>, VecChunker<((K,()),T,R)>, VecMerger<((K, ()), T, R)>>;
 /// A builder for ordered lists.
 pub type RcOrdKeyBuilder<K, T, R> = RcBuilder<OrdKeyBuilder<Vector<((K,()),T,R)>, Vec<((K,()),T,R)>>>;
 
@@ -73,14 +73,14 @@ pub type RcOrdKeyBuilder<K, T, R> = RcBuilder<OrdKeyBuilder<Vector<((K,()),T,R)>
 /// A trace implementation backed by columnar storage.
 pub type ColKeySpine<K, T, R> = Spine<Rc<OrdKeyBatch<TStack<((K,()),T,R)>>>>;
 /// A batcher for columnar storage
-pub type ColKeyBatcher<K, T, R> = MergeBatcher<Vec<((K,()),T,R)>, ColumnationChunker<((K,()),T,R)>, ColumnationMerger<((K,()),T,R)>, T>;
+pub type ColKeyBatcher<K, T, R> = MergeBatcher<Vec<((K,()),T,R)>, ColumnationChunker<((K,()),T,R)>, ColumnationMerger<((K,()),T,R)>>;
 /// A builder for columnar storage
 pub type ColKeyBuilder<K, T, R> = RcBuilder<OrdKeyBuilder<TStack<((K,()),T,R)>, TimelyStack<((K,()),T,R)>>>;
 
 /// A trace implementation backed by flatcontainer storage.
 pub type FlatKeySpine<L> = Spine<Rc<OrdKeyBatch<L>>>;
 /// A batcher for flatcontainer storage.
-pub type FlatKeyBatcher<R, C> = MergeBatcher<C, ContainerChunker<FlatStack<R>>, FlatcontainerMerger<R>, <R as MergerChunk>::TimeOwned>;
+pub type FlatKeyBatcher<R, C> = MergeBatcher<C, ContainerChunker<FlatStack<R>>, FlatcontainerMerger<R>>;
 /// A builder for flatcontainer storage.
 pub type FlatKeyBuilder<L, R> = RcBuilder<OrdKeyBuilder<L, FlatStack<R>>>;
 
@@ -96,7 +96,7 @@ pub type FlatKeyBuilderDefault<K, T, R> = FlatKeyBuilder<FlatLayout<<K as Region
 /// A trace implementation backed by columnar storage.
 pub type PreferredSpine<K, V, T, R> = Spine<Rc<OrdValBatch<Preferred<K,V,T,R>>>>;
 /// A batcher for columnar storage.
-pub type PreferredBatcher<K, V, T, R> = MergeBatcher<Vec<((<K as ToOwned>::Owned,<V as ToOwned>::Owned),T,R)>, ColumnationChunker<((<K as ToOwned>::Owned,<V as ToOwned>::Owned),T,R)>, ColumnationMerger<((<K as ToOwned>::Owned,<V as ToOwned>::Owned),T,R)>,T>;
+pub type PreferredBatcher<K, V, T, R> = MergeBatcher<Vec<((<K as ToOwned>::Owned,<V as ToOwned>::Owned),T,R)>, ColumnationChunker<((<K as ToOwned>::Owned,<V as ToOwned>::Owned),T,R)>, ColumnationMerger<((<K as ToOwned>::Owned,<V as ToOwned>::Owned),T,R)>>;
 /// A builder for columnar storage.
 pub type PreferredBuilder<K, V, T, R> = RcBuilder<OrdValBuilder<Preferred<K,V,T,R>, TimelyStack<((<K as ToOwned>::Owned,<V as ToOwned>::Owned),T,R)>>>;
 
diff --git a/src/trace/implementations/rhh.rs b/src/trace/implementations/rhh.rs
index 08f26ade5..5a57d37a5 100644
--- a/src/trace/implementations/rhh.rs
+++ b/src/trace/implementations/rhh.rs
@@ -25,7 +25,7 @@ use self::val_batch::{RhhValBatch, RhhValBuilder};
 /// A trace implementation using a spine of ordered lists.
 pub type VecSpine<K, V, T, R> = Spine<Rc<RhhValBatch<Vector<((K,V),T,R)>>>>;
 /// A batcher for ordered lists.
-pub type VecBatcher<K,V,T,R> = MergeBatcher<Vec<((K,V),T,R)>, VecChunker<((K,V),T,R)>, VecMerger<((K, V), T, R)>, T>;
+pub type VecBatcher<K,V,T,R> = MergeBatcher<Vec<((K,V),T,R)>, VecChunker<((K,V),T,R)>, VecMerger<((K, V), T, R)>>;
 /// A builder for ordered lists.
 pub type VecBuilder<K,V,T,R> = RcBuilder<RhhValBuilder<Vector<((K,V),T,R)>, Vec<((K,V),T,R)>>>;
 
@@ -35,7 +35,7 @@ pub type VecBuilder<K,V,T,R> = RcBuilder<RhhValBuilder<Vector<((K,V),T,R)>, Vec<
 /// A trace implementation backed by columnar storage.
 pub type ColSpine<K, V, T, R> = Spine<Rc<RhhValBatch<TStack<((K,V),T,R)>>>>;
 /// A batcher for columnar storage.
-pub type ColBatcher<K,V,T,R> = MergeBatcher<Vec<((K,V),T,R)>, ColumnationChunker<((K,V),T,R)>, ColumnationMerger<((K,V),T,R)>, T>;
+pub type ColBatcher<K,V,T,R> = MergeBatcher<Vec<((K,V),T,R)>, ColumnationChunker<((K,V),T,R)>, ColumnationMerger<((K,V),T,R)>>;
 /// A builder for columnar storage.
 pub type ColBuilder<K,V,T,R> = RcBuilder<RhhValBuilder<TStack<((K,V),T,R)>, TimelyStack<((K,V),T,R)>>>;