I have unchecked "Import Materials" but two texture maps are still being imported.

In most of my projects I use a script like this (place it in the Assets/Editor folder):

 using UnityEngine;
 using UnityEditor;
 
 public class FBXImportSettings : AssetPostprocessor
 {
     void OnPreprocessModel()
     {
         ModelImporter importer = (ModelImporter)assetImporter;
 
         // Don't import materials
         importer.importMaterials = false;
     }
 }

It will disable material imports. You can also extend this script to automatically set the model scale, animation stuff etc. to your liking.