diff --git a/src/niclips/figures/bold.py b/src/niclips/figures/bold.py
index c9375a2..b4ac5bf 100644
--- a/src/niclips/figures/bold.py
+++ b/src/niclips/figures/bold.py
@@ -62,7 +62,6 @@ def cluster_timeseries(
 def carpet_plot(
     bold: nib.Nifti1Image,
     out: StrPath | None = None,
-    *,
     label: nib.Nifti1Image | None = None,
     n_voxels: int = 2000,
     seed: int = 42,
@@ -157,7 +156,6 @@ def carpet_plot(
 def bold_mean_std(
     bold: nib.Nifti1Image,
     out: StrPath | None = None,
-    *,
     std_vmax_ratio: float = 0.1,
     figure: str | None = None,
     **kwargs,
diff --git a/src/niclips/figures/dwi.py b/src/niclips/figures/dwi.py
index d21d9d3..f96ce58 100644
--- a/src/niclips/figures/dwi.py
+++ b/src/niclips/figures/dwi.py
@@ -41,7 +41,6 @@ def _get_bval_indices(bvals: np.ndarray, bval: int) -> np.ndarray:
 def visualize_qspace(
     dwi: nib.Nifti1Image,
     out: StrPath | None = None,
-    *,
     thresh: int = 10,
     figure: str | None = None,
 ) -> FuncAnimation:
@@ -93,7 +92,6 @@ def _rotate(angle: int) -> None:
 def three_view_per_shell(
     dwi: nib.Nifti1Image,
     out: StrPath | None = None,
-    *,
     thresh: int = 10,
     replace_str: str = "bval",
 ) -> list[nib.Nifti1Image]:
@@ -125,7 +123,6 @@ def three_view_per_shell(
 def signal_per_volume(
     dwi: nib.Nifti1Image,
     out: StrPath | None = None,
-    *,
     fontsize: int = 14,
     figure: str | None = None,
 ) -> None:
diff --git a/src/niclips/figures/multi_view.py b/src/niclips/figures/multi_view.py
index cb0d7f3..a0224b5 100644
--- a/src/niclips/figures/multi_view.py
+++ b/src/niclips/figures/multi_view.py
@@ -89,7 +89,6 @@ def multi_view_frame(
 def three_view_frame(
     img: NiftiLike,
     out: StrPath | None = None,
-    *,
     coord: tuple[float, float, float] | None = None,
     idx: int | None = 0,
     vmin: float | None = None,
@@ -138,7 +137,6 @@ def three_view_frame(
 def three_view_video(
     img: nib.Nifti1Image,
     out: StrPath,
-    *,
     coord: tuple[float, float, float] | None = None,
     vmin: float | None = None,
     vmax: float | None = None,
@@ -181,7 +179,6 @@ def three_view_video(
 def slice_video(
     img: NiftiLike,
     out: StrPath,
-    *,
     axis: int = 2,
     idx: int | None = 0,
     vmin: float | None = None,
diff --git a/src/niftyone/figures/generator.py b/src/niftyone/figures/generator.py
index ce6ff65..01582e6 100644
--- a/src/niftyone/figures/generator.py
+++ b/src/niftyone/figures/generator.py
@@ -1,17 +1,16 @@
-"""Generator classes for different views."""
+"""Figure generation class for different views."""
 
 import logging
 from abc import ABC
 from functools import reduce
 from pathlib import Path
+from types import MappingProxyType
 from typing import Any, Callable, Generic, TypeVar
 
 import matplotlib.pyplot as plt
 import nibabel as nib
 import pandas as pd
 from bids2table import BIDSEntities, BIDSTable
-from matplotlib.figure import Figure
-from PIL.Image import Image
 
 import niclips.image as noimg
 
@@ -37,45 +36,34 @@ def create_generator(
     queries: list[str],
 ) -> "ViewGenerator":
     """Function to create generator."""
-    if view_kwargs is None:
-        view_kwargs = {}
+    view_kwargs = view_kwargs or {}
 
     try:
         generator_cls = generator_registry[view]
-        generator_instance = generator_cls(queries, join_entities, view_kwargs)
-        return generator_instance
+        return generator_cls(queries, join_entities, view_kwargs)
     except KeyError:
-        msg = f"Generator for '{view}' for not found in registry."
-        raise KeyError(msg)
+        raise KeyError(f"Generator for '{view}' for not found in registry.")
 
 
 def create_generators(config: dict[str, Any]) -> list["ViewGenerator"]:
     """Create selected generators dynamically from config with default settings."""
-    generators: list["ViewGenerator"] = []
-
-    for group in config.get("figures", {}).values():
-        queries = group.get("queries", [])
-        join_entities = group.get("join_entities", ["sub", "ses"])
-        views = group.get("views", {})
-
-        for view, view_kwargs in views.items():
-            generators.append(
-                create_generator(
-                    view=view,
-                    view_kwargs=view_kwargs,
-                    join_entities=join_entities,
-                    queries=queries,
-                )
-            )
-
-    return generators
+    return [
+        create_generator(
+            view=view,
+            view_kwargs=view_kwargs,
+            join_entities=group.get("join_entities", ["sub", "ses"]),
+            queries=group.get("queries", []),
+        )
+        for group in config.get("figures", {}).values()
+        for view, view_kwargs in group.get("views", {}).items()
+    ]
 
 
 class ViewGenerator(ABC, Generic[T]):
     """Base view generator class."""
 
     entities: dict[str, Any] | None = None
-    view_fn: Callable[[nib.Nifti1Image, Path], Image | Figure | None] | None = None
+    view_fn: Callable | None = None
 
     def __init__(
         self,
@@ -84,7 +72,7 @@ def __init__(
         view_kwargs: dict[str, Any],
     ) -> None:
         self.queries = queries
-        self.view_kwargs = view_kwargs
+        self.view_kwargs = MappingProxyType(view_kwargs)  # Immutable dict
         self.join_entities = join_entities or []
 
     def __call__(
@@ -93,15 +81,13 @@ def __call__(
         out_dir: Path,
         overwrite: bool,
     ) -> None:
-        # Filters by entity (via string query)
+        # Filters by entities via string query
         # First query is for main image, subsequent are for overlays
         query_dfs = [table.ent.query(q) for q in self.queries]
         indexed_dfs = [
-            (
-                df.reset_index(names=f"index_{ii}", drop=False).loc[
-                    :, [f"index_{ii}"] + self.join_entities
-                ]
-            )
+            df.reset_index(names=f"index_{ii}", drop=False)[
+                [f"index_{ii}"] + self.join_entities
+            ]
             for ii, df in enumerate(query_dfs)
         ]
         joined = reduce(
@@ -110,9 +96,7 @@ def __call__(
             ),
             indexed_dfs,
         )
-        indices = [
-            joined[col].values for col in joined.columns if col.startswith("index_")
-        ]
+        indices = (joined[col].values for col in joined if col.startswith("index_"))
 
         for inds in zip(*indices):
             records = [table.nested.loc[ind] for ind in inds]
@@ -123,7 +107,31 @@ def _figure_name(self) -> None:
         if "figure" in self.view_kwargs:
             assert self.entities
             self.entities["extra_entities"]["figure"] = self.view_kwargs["figure"]
-            del self.view_kwargs["figure"]
+            # del self.view_kwargs["figure"]
+
+    def _load_image(self, record: pd.Series, log: bool = False) -> nib.Nifti1Image:
+        """Helper to load image."""
+        img_path = Path(record["finfo"]["file_path"])
+        if log:
+            logging.info("Processing %s", img_path)
+        img = nib.nifti1.load(img_path)
+
+        return noimg.to_iso_ras(img)
+
+    def _load_overlays(self, overlay_records: list[pd.Series]) -> list[nib.Nifti1Image]:
+        """Helper to load overlays."""
+        overlays = []
+        for overlay_record in overlay_records:
+            overlays.append(self._load_image(record=overlay_record))
+        return overlays
+
+    def _update_out_path(self, record: pd.Series, out_dir: Path) -> Path:
+        """Generates the output figure file path."""
+        self._figure_name()
+        existing_entities = BIDSEntities.from_dict(record["ent"])
+        out_path = existing_entities.with_update(self.entities).to_path(prefix=out_dir)
+        out_path.parent.mkdir(exist_ok=True, parents=True)
+        return out_path
 
     def generate(
         self,
@@ -135,30 +143,16 @@ def generate(
         if not self.view_fn:
             raise ValueError("View is not provided, unable to create generator.")
 
-        # Update figure name if necessary
-        self._figure_name()
-
-        img_path = Path(records[0]["finfo"]["file_path"])
-        logging.info("Processing: %s", img_path)
-
-        img = nib.nifti1.load(img_path)
-        img = noimg.to_iso_ras(img)
-
-        # Handle overlays
-        if len(records) > 1:
-            overlays: list[nib.Nifti1Image] = []
-            for overlay_record in records[1:]:
-                overlay_path = Path(overlay_record["finfo"]["file_path"])
-                overlay = nib.nifti1.load(overlay_path)
-                overlays.append(noimg.to_iso_ras(overlay))
-            self.view_kwargs["overlay"] = overlays
-
-        existing_entities = BIDSEntities.from_dict(records[0]["ent"])
-        out_path = existing_entities.with_update(self.entities).to_path(prefix=out_dir)
-        out_path.parent.mkdir(exist_ok=True, parents=True)
+        img = self._load_image(record=records[0], log=True)
+        overlays = (
+            self._load_overlays(overlay_records=records[1:])
+            if len(records) > 1
+            else None
+        )
+        out_path = self._update_out_path(records[0], out_dir)
 
         if not out_path.exists() or overwrite:
             logging.info("Generating %s", out_path)
-            self.view_fn(img, out_path, **self.view_kwargs)
+            self.view_fn(img, out_path, overlays=overlays, **self.view_kwargs)
 
         plt.close("all")
diff --git a/tests/unit/niftyone/figures/test_generator.py b/tests/unit/niftyone/figures/test_generator.py
index 5ec83a6..0df3e4d 100644
--- a/tests/unit/niftyone/figures/test_generator.py
+++ b/tests/unit/niftyone/figures/test_generator.py
@@ -1,4 +1,4 @@
-from collections.abc import Generator
+from collections.abc import Generator, Mapping
 from pathlib import Path
 from typing import Any
 from unittest.mock import MagicMock
@@ -90,7 +90,7 @@ def test_create_generators_view_kwargs(
         )
         assert isinstance(generator, ViewGenerator)
         assert generator.queries == ["suffix == 'T1w'"]
-        assert isinstance(generator.view_kwargs, dict)
+        assert isinstance(generator.view_kwargs, Mapping)
 
     def test_create_generators(self, setup_registry: Generator):
         config = {