don't shrink embeddings unless told to

src/axolotl/utils/config/models/input/v0_4_1/__init__.py

@@ -667,6 +667,8 @@ class AxolotlInputConfig(
     auto_resume_from_checkpoints: Optional[bool] = None
     resize_token_embeddings_to_32x: Optional[bool] = None
     mean_resizing_embeddings: Optional[bool] = False
+    # optionally shrink the embeddings when the tokenizer vocab size is smaller
+    shrink_embeddings: Optional[bool] = None
 
     rl: Optional[RLType] = None
     reward_model: Optional[bool] = None

src/axolotl/utils/models.py

@@ -1053,9 +1053,12 @@ class ModelLoader:
             if self.cfg.resize_token_embeddings_to_32x
             else len(self.tokenizer)
         )
-        if (
-            hasattr(self.model, "get_input_embeddings")
-            and self.model.get_input_embeddings().num_embeddings != embeddings_len
+        if hasattr(self.model, "get_input_embeddings") and (
+            self.model.get_input_embeddings().num_embeddings < embeddings_len
+            or (
+                self.model.get_input_embeddings().num_embeddings > embeddings_len
+                and self.cfg.shrink_embeddings
+            )
         ):
             resize_kwargs = {}
             if self.cfg.mean_resizing_embeddings is not None: