diff --git a/bayesflow/utils/_docs/_populate_all.py b/bayesflow/utils/_docs/_populate_all.py
index 50da8048b..d9718c2f5 100644
--- a/bayesflow/utils/_docs/_populate_all.py
+++ b/bayesflow/utils/_docs/_populate_all.py
@@ -1,4 +1,5 @@
-import inspect
+import sys
+import types
 
 
 def _add_imports_to_all(include_modules: bool | list[str] = False, exclude: list[str] | None = None):
@@ -6,18 +7,25 @@ def _add_imports_to_all(include_modules: bool | list[str] = False, exclude: list
     if not isinstance(include_modules, (bool, list)):
         raise ValueError("include_modules must be a boolean or a list of strings")
 
-    exclude = exclude or []
-    calling_module = inspect.stack()[1]
-    local_stack = calling_module[0]
-    global_vars = local_stack.f_globals
-    all_vars = global_vars["__all__"] if "__all__" in global_vars else []
-    included_vars = []
-    for var_name in set(global_vars.keys()):
-        if inspect.ismodule(global_vars[var_name]):
-            if include_modules is True and var_name not in exclude and not var_name.startswith("_"):
-                included_vars.append(var_name)
-            elif isinstance(include_modules, list) and var_name in include_modules:
-                included_vars.append(var_name)
-        elif var_name not in exclude and not var_name.startswith("_"):
-            included_vars.append(var_name)
-    global_vars["__all__"] = sorted(list(set(all_vars).union(included_vars)))
+    exclude_set = set(exclude or [])
+    contains = exclude_set.__contains__
+    mod_type = types.ModuleType
+    frame = sys._getframe(1)
+    g: dict = frame.f_globals
+    existing = set(g.get("__all__", []))
+
+    to_add = []
+    include_list = include_modules if isinstance(include_modules, list) else ()
+    inc_all = include_modules is True
+
+    for name, val in g.items():
+        if name.startswith("_") or contains(name):
+            continue
+
+        if isinstance(val, mod_type):
+            if inc_all or name in include_list:
+                to_add.append(name)
+        else:
+            to_add.append(name)
+
+    g["__all__"] = sorted(existing.union(to_add))
diff --git a/bayesflow/utils/serialization.py b/bayesflow/utils/serialization.py
index c6e804c74..500264f05 100644
--- a/bayesflow/utils/serialization.py
+++ b/bayesflow/utils/serialization.py
@@ -4,6 +4,7 @@
 import inspect
 import keras
 import numpy as np
+import sys
 
 # this import needs to be exactly like this to work with monkey patching
 from keras.saving import deserialize_keras_object
@@ -97,7 +98,10 @@ def deserialize(obj, custom_objects=None, safe_mode=True, **kwargs):
             # we marked this as a type during serialization
             obj = obj[len(_type_prefix) :]
             tp = keras.saving.get_registered_object(
-                obj, custom_objects=custom_objects, module_objects=builtins.__dict__ | np.__dict__
+                # TODO: can we pass module objects without overwriting numpy's dict with builtins?
+                obj,
+                custom_objects=custom_objects,
+                module_objects=np.__dict__ | builtins.__dict__,
             )
             if tp is None:
                 raise ValueError(
@@ -117,10 +121,9 @@ def deserialize(obj, custom_objects=None, safe_mode=True, **kwargs):
 @allow_args
 def serializable(cls, package=None, name=None):
     if package is None:
-        # get the calling module's name, e.g. "bayesflow.networks.inference_network"
-        stack = inspect.stack()
-        module = inspect.getmodule(stack[1][0])
-        package = copy(module.__name__)
+        frame = sys._getframe(1)
+        g = frame.f_globals
+        package = g.get("__name__", "bayesflow")
 
     if name is None:
         name = copy(cls.__name__)
diff --git a/examples/Linear_Regression_Starter.ipynb b/examples/Linear_Regression_Starter.ipynb
index f728767a0..b352a4e04 100644
--- a/examples/Linear_Regression_Starter.ipynb
+++ b/examples/Linear_Regression_Starter.ipynb
@@ -38,6 +38,7 @@
    "outputs": [],
    "source": [
     "import numpy as np\n",
+    "from pathlib import Path\n",
     "\n",
     "import keras\n",
     "import bayesflow as bf"
@@ -955,7 +956,9 @@
    "outputs": [],
    "source": [
     "# Recommended - full serialization (checkpoints folder must exist)\n",
-    "workflow.approximator.save(filepath=\"checkpoints/regression.keras\")\n",
+    "filepath = Path(\"checkpoints\") / \"regression.keras\"\n",
+    "filepath.parent.mkdir(exist_ok=True)\n",
+    "workflow.approximator.save(filepath=filepath)\n",
     "\n",
     "# Not recommended due to adapter mismatches - weights only\n",
     "# approximator.save_weights(filepath=\"checkpoints/regression.h5\")"
@@ -975,7 +978,7 @@
    "outputs": [],
    "source": [
     "# Load approximator\n",
-    "approximator = keras.saving.load_model(\"checkpoints/regression.keras\")"
+    "approximator = keras.saving.load_model(filepath)"
    ]
   },
   {
diff --git a/examples/Lotka_Volterra_Point_Estimation_and_Expert_Stats.ipynb b/examples/Lotka_Volterra_Point_Estimation_and_Expert_Stats.ipynb
index 3dc7c1b25..d52355fa6 100644
--- a/examples/Lotka_Volterra_Point_Estimation_and_Expert_Stats.ipynb
+++ b/examples/Lotka_Volterra_Point_Estimation_and_Expert_Stats.ipynb
@@ -37,6 +37,7 @@
    "source": [
     "import matplotlib.pyplot as plt\n",
     "import numpy as np\n",
+    "from pathlib import Path\n",
     "import seaborn as sns\n",
     "\n",
     "import scipy\n",
@@ -748,7 +749,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "checkpoint_path = \"checkpoints/model.keras\"\n",
+    "checkpoint_path = Path(\"checkpoints\") / \"model.keras\"\n",
+    "checkpoint_path.parent.mkdir(exist_ok=True)\n",
     "keras.saving.save_model(point_inference_workflow.approximator, checkpoint_path)"
    ]
   },
diff --git a/pyproject.toml b/pyproject.toml
index bdb61fcca..6f1df3a4b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,6 +37,8 @@ all = [
     "jupyter",
     "jupyterlab",
     "nbconvert",
+    "ipython",
+    "ipykernel",
     "pre-commit",
     "ruff",
     "tox",
@@ -72,6 +74,8 @@ docs = [
 ]
 test = [
     "nbconvert",
+    "ipython",
+    "ipykernel",
     "pytest",
     "pytest-cov",
     "pytest-rerunfailures",
diff --git a/tests/test_examples/test_examples.py b/tests/test_examples/test_examples.py
index 42cf7cf53..245052636 100644
--- a/tests/test_examples/test_examples.py
+++ b/tests/test_examples/test_examples.py
@@ -3,6 +3,7 @@
 from tests.utils import run_notebook
 
 
+@pytest.mark.skip(reason="requires setting up Stan")
 @pytest.mark.slow
 def test_bayesian_experimental_design(examples_path):
     run_notebook(examples_path / "Bayesian_Experimental_Design.ipynb")
@@ -30,7 +31,7 @@ def test_one_sample_ttest(examples_path):
 
 @pytest.mark.slow
 def test_sir_posterior_estimation(examples_path):
-    run_notebook(examples_path / "SIR_Posterior_estimation.ipynb")
+    run_notebook(examples_path / "SIR_Posterior_Estimation.ipynb")
 
 
 @pytest.mark.slow
diff --git a/tests/test_networks/conftest.py b/tests/test_networks/conftest.py
index 84c011812..01ea5ad70 100644
--- a/tests/test_networks/conftest.py
+++ b/tests/test_networks/conftest.py
@@ -85,6 +85,7 @@ def typical_point_inference_network_subnet():
         "spline_coupling_flow",
         "flow_matching",
         "free_form_flow",
+        "consistency_model",
     ],
     scope="function",
 )
@@ -106,7 +107,8 @@ def inference_network_subnet(request):
 
 
 @pytest.fixture(
-    params=["affine_coupling_flow", "spline_coupling_flow", "flow_matching", "free_form_flow"], scope="function"
+    params=["affine_coupling_flow", "spline_coupling_flow", "flow_matching", "free_form_flow", "consistency_model"],
+    scope="function",
 )
 def generative_inference_network(request):
     return request.getfixturevalue(request.param)
diff --git a/tests/test_networks/test_inference_networks.py b/tests/test_networks/test_inference_networks.py
index 880a4d082..7766b29f9 100644
--- a/tests/test_networks/test_inference_networks.py
+++ b/tests/test_networks/test_inference_networks.py
@@ -36,13 +36,21 @@ def test_variable_batch_size(inference_network, random_samples, random_condition
         else:
             new_conditions = keras.ops.zeros((bs,) + keras.ops.shape(random_conditions)[1:])
 
-        inference_network(new_input, conditions=new_conditions)
+        try:
+            inference_network(new_input, conditions=new_conditions)
+        except NotImplementedError:
+            # network is not invertible
+            pass
         inference_network(new_input, conditions=new_conditions, inverse=True)
 
 
 @pytest.mark.parametrize("density", [True, False])
 def test_output_structure(density, generative_inference_network, random_samples, random_conditions):
-    output = generative_inference_network(random_samples, conditions=random_conditions, density=density)
+    try:
+        output = generative_inference_network(random_samples, conditions=random_conditions, density=density)
+    except NotImplementedError:
+        # network not invertible
+        return
 
     if density:
         assert isinstance(output, tuple)
@@ -57,9 +65,13 @@ def test_output_structure(density, generative_inference_network, random_samples,
 
 
 def test_output_shape(generative_inference_network, random_samples, random_conditions):
-    forward_output, forward_log_density = generative_inference_network(
-        random_samples, conditions=random_conditions, density=True
-    )
+    try:
+        forward_output, forward_log_density = generative_inference_network(
+            random_samples, conditions=random_conditions, density=True
+        )
+    except NotImplementedError:
+        # network is not invertible, not forward function available
+        return
 
     assert keras.ops.shape(forward_output) == keras.ops.shape(random_samples)
     assert keras.ops.shape(forward_log_density) == (keras.ops.shape(random_samples)[0],)
@@ -74,9 +86,13 @@ def test_output_shape(generative_inference_network, random_samples, random_condi
 
 def test_cycle_consistency(generative_inference_network, random_samples, random_conditions):
     # cycle-consistency means the forward and inverse methods are inverses of each other
-    forward_output, forward_log_density = generative_inference_network(
-        random_samples, conditions=random_conditions, density=True
-    )
+    try:
+        forward_output, forward_log_density = generative_inference_network(
+            random_samples, conditions=random_conditions, density=True
+        )
+    except NotImplementedError:
+        # network is not invertible, cycle consistency cannot be tested.
+        return
     inverse_output, inverse_log_density = generative_inference_network(
         forward_output, conditions=random_conditions, density=True, inverse=True
     )
@@ -88,7 +104,11 @@ def test_cycle_consistency(generative_inference_network, random_samples, random_
 def test_density_numerically(generative_inference_network, random_samples, random_conditions):
     from bayesflow.utils import jacobian
 
-    output, log_density = generative_inference_network(random_samples, conditions=random_conditions, density=True)
+    try:
+        output, log_density = generative_inference_network(random_samples, conditions=random_conditions, density=True)
+    except NotImplementedError:
+        # network does not support density estimation
+        return
 
     def f(x):
         return generative_inference_network(x, conditions=random_conditions)
diff --git a/tests/test_utils/test_dispatch.py b/tests/test_utils/test_dispatch.py
index 8fc0f91f0..85e326445 100644
--- a/tests/test_utils/test_dispatch.py
+++ b/tests/test_utils/test_dispatch.py
@@ -3,6 +3,7 @@
 
 # Import the dispatch functions
 from bayesflow.utils import find_network, find_permutation, find_pooling, find_recurrent_net
+from tests.utils import assert_allclose
 
 # --- Tests for find_network.py ---
 
@@ -118,23 +119,21 @@ def test_find_pooling_mean():
     # Check that a keras Lambda layer is returned
     assert isinstance(pooling, keras.layers.Lambda)
     # Test that the lambda function produces a mean when applied to a sample tensor.
-    import numpy as np
 
-    sample = np.array([[1, 2], [3, 4]])
+    sample = keras.ops.convert_to_tensor([[1, 2], [3, 4]])
     # Keras Lambda layers expect tensors via call(), here we simply call the layer's function.
     result = pooling.call(sample)
-    np.testing.assert_allclose(result, sample.mean(axis=-2))
+    assert_allclose(result, keras.ops.mean(sample, axis=-2))
 
 
 @pytest.mark.parametrize("name,func", [("max", keras.ops.max), ("min", keras.ops.min)])
 def test_find_pooling_max_min(name, func):
     pooling = find_pooling(name)
     assert isinstance(pooling, keras.layers.Lambda)
-    import numpy as np
 
-    sample = np.array([[1, 2], [3, 4]])
+    sample = keras.ops.convert_to_tensor([[1, 2], [3, 4]])
     result = pooling.call(sample)
-    np.testing.assert_allclose(result, func(sample, axis=-2))
+    assert_allclose(result, func(sample, axis=-2))
 
 
 def test_find_pooling_learnable(monkeypatch):
diff --git a/tests/utils/jupyter.py b/tests/utils/jupyter.py
index fad68444b..f905e1a0c 100644
--- a/tests/utils/jupyter.py
+++ b/tests/utils/jupyter.py
@@ -1,11 +1,25 @@
 import nbformat
 from nbconvert.preprocessors import ExecutePreprocessor
 
+from pathlib import Path
+import shutil
+
 
 def run_notebook(path):
+    path = Path(path)
+    checkpoint_path = path.parent / "checkpoints"
+    # only clean up if the directory did not exist before the test
+    cleanup_checkpoints = not checkpoint_path.exists()
     with open(str(path)) as f:
         nb = nbformat.read(f, nbformat.NO_CONVERT)
 
-    kernel = ExecutePreprocessor(timeout=600, kernel_name="python3")
+    kernel = ExecutePreprocessor(timeout=600, kernel_name="python3", resources={"metadata": {"path": path.parent}})
+
+    try:
+        result = kernel.preprocess(nb)
+    finally:
+        if cleanup_checkpoints and checkpoint_path.exists():
+            # clean up if the directory was created by the test
+            shutil.rmtree(checkpoint_path)
 
-    return kernel.preprocess(nb)
+    return result