diff --git a/greater_tables/gtconfig.py b/greater_tables/gtconfig.py
index da7cc09..7cd9459 100644
--- a/greater_tables/gtconfig.py
+++ b/greater_tables/gtconfig.py
@@ -9,7 +9,7 @@ Also includes functions for writing editable config templates and loading from Y
 
 
 from pathlib import Path
-from typing import Optional, Union, Literal
+from typing import Optional, Union, Literal, Callable, Any
 import yaml
 
 from pydantic import BaseModel, Field, ValidationError, ConfigDict
@@ -56,8 +56,8 @@ class Configurator(BaseModel):
         None, description="Optional fallback formatter f-string"
     )
 
-    table_float_format: Optional[str] = Field(
-        None, description="Float format string for the entire table; overrides column-specific formats"
+    table_float_format: Optional[Union[str, Callable[[Any, str], str]]] = Field(
+        None, description="Float format function or format string for the entire table; overrides column-specific formats"
     )
     table_hrule_width: int = Field(
         1, description="Width of top, bottom, and header horizontal rules"
diff --git a/greater_tables/gtcore.py b/greater_tables/gtcore.py
index 112a8bb..8315edf 100644
--- a/greater_tables/gtcore.py
+++ b/greater_tables/gtcore.py
@@ -2459,12 +2459,12 @@ class GT(object):
         def escape_index(idx):
             if isinstance(idx, pd.MultiIndex):
                 return pd.MultiIndex.from_tuples(
-                    [tuple(escape_tex_outside_math(x) for x in tup) for tup in idx],
-                    names=[escape_tex_outside_math(n) if n else n for n in idx.names]
+                    [tuple(GT.escape_tex_outside_math(x) for x in tup) for tup in idx],
+                    names=[GT.escape_tex_outside_math(n) if n else n for n in idx.names]
                 )
             else:
-                return pd.Index([escape_tex_outside_math(x) for x in idx],
-                             name=escape_tex_outside_math(idx.name) if idx.name else None)
+                return pd.Index([GT.escape_tex_outside_math(x) for x in idx],
+                             name=GT.escape_tex_outside_math(idx.name) if idx.name else None)
 
         df.index = escape_index(df.index)
         df.columns = escape_index(df.columns)