Added use_error_term to hooked sae transformer

sae_lens/analysis/hooked_sae_transformer.py

@@ -75,7 +75,7 @@ def __init__(
         super().__init__(*model_args, **model_kwargs)
         self.acts_to_saes: Dict[str, SAE] = {}
 
-    def add_sae(self, sae: SAE):
+    def add_sae(self, sae: SAE, use_error_term: Optional[bool] = None):
         """Attaches an SAE to the model
 
         WARNING: This sae will be permanantly attached until you remove it with reset_saes. This function will also overwrite any existing SAE attached to the same hook point.
@@ -90,6 +90,9 @@ def add_sae(self, sae: SAE):
             )
             return
 
+        if use_error_term is not None:
+            sae.use_error_term = True
+
         self.acts_to_saes[act_name] = sae
         set_deep_attr(self, act_name, sae)
         self.setup()