diff --git a/sae/config.py b/sae/config.py
index acf0ab6..eedb268 100644
--- a/sae/config.py
+++ b/sae/config.py
@@ -1,5 +1,4 @@
 from dataclasses import dataclass
-from typing import AbstractSet
 
 from simple_parsing import Serializable, list_field
 
@@ -68,12 +67,6 @@ class TrainConfig(Serializable):
     save_every: int = 1000
     """Save SAEs every `save_every` steps."""
 
-    sample_dims: AbstractSet[int] = frozenset({0, 1})
-    """Dimensions containing SAE inputs."""
-
-    feature_dims: AbstractSet[int] = frozenset({2})
-    """Dimensions of SAE inputs."""
-    
     log_to_wandb: bool = True
     run_name: str | None = None
     wandb_log_frequency: int = 1
diff --git a/sae/trainer.py b/sae/trainer.py
index 0026e04..758dcb8 100644
--- a/sae/trainer.py
+++ b/sae/trainer.py
@@ -36,10 +36,11 @@ def __init__(
             found_hookpoints = natsorted(raw_hookpoints)
 
             if not found_hookpoints:
-                print(f"No modules matched the pattern(s) {cfg.hookpoints}")
-                print("Available modules:")
-                for name, _ in model.named_modules():
-                    print(name)
+                error_msg = f"""No modules matched the pattern(s) {cfg.hookpoints}
+
+Available modules:
+{chr(10).join(name for name, _ in model.named_modules())}"""
+                raise ValueError(error_msg)
 
             cfg.hookpoints = found_hookpoints
 
@@ -63,8 +64,7 @@ def __init__(
 
         device = model.device
         dummy_inputs = dummy_inputs if dummy_inputs is not None else model.dummy_inputs
-        input_widths = resolve_widths(model, cfg.hookpoints, dummy_inputs, 
-                                      dims=cfg.feature_dims)
+        input_widths = resolve_widths(model, cfg.hookpoints, dummy_inputs)
         unique_widths = set(input_widths.values())
 
         if cfg.distribute_modules and len(unique_widths) > 1:
@@ -215,11 +215,11 @@ def hook(module: nn.Module, inputs, outputs):
                 outputs = outputs[0]
 
             name = module_to_name[module]
-            output_dict[name] = outputs
+            output_dict[name] = outputs.flatten(0, -2)
 
             # Remember the inputs if we're training a transcoder
             if self.cfg.transcode:
-                input_dict[name] = inputs
+                input_dict[name] = inputs.flatten(0, -2)
 
         for batch in dl:
             input_dict.clear()
@@ -248,13 +248,6 @@ def hook(module: nn.Module, inputs, outputs):
                 inputs = input_dict.get(name, outputs)
                 raw = self.saes[name]           # 'raw' never has a DDP wrapper
 
-                outputs = outputs.permute(*self.cfg.sample_dims, *self.cfg.feature_dims)
-                outputs = outputs.reshape(-1, raw.d_in)
-
-                if self.cfg.transcode:
-                    inputs = inputs.permute(*self.cfg.sample_dims, *self.cfg.feature_dims)
-                    inputs = inputs.reshape(-1, raw.d_in)
-
                 # On the first iteration, initialize the decoder bias
                 if self.global_step == 0:
                     # NOTE: The all-cat here could conceivably cause an OOM in some
diff --git a/sae/utils.py b/sae/utils.py
index 4d5e483..5f39d20 100644
--- a/sae/utils.py
+++ b/sae/utils.py
@@ -1,6 +1,5 @@
 import os
 from typing import Any, Type, TypeVar, cast
-from math import prod
 
 import torch
 from accelerate.utils import send_to_device
@@ -63,7 +62,7 @@ def get_layer_list(model: PreTrainedModel) -> tuple[str, nn.ModuleList]:
 @torch.inference_mode()
 def resolve_widths(
     model: PreTrainedModel, module_names: list[str], dummy_inputs: dict[str, Tensor], 
-    dims: set[int] = {-1},
+    dim: int = -1,
 ) -> dict[str, int]:
     """Find number of output dimensions for the specified modules."""
     module_to_name = {
@@ -77,8 +76,7 @@ def hook(module, _, output):
             output, *_ = output
 
         name = module_to_name[module]
-
-        shapes[name] = prod(output.shape[d] for d in dims)
+        shapes[name] = output.shape[dim]
 
     handles = [
         mod.register_forward_hook(hook) for mod in module_to_name