Is there any progress in getting this to work for categories and subcategories? I had a bash at it myself, using your amends as a basis but unfortunately my dev skills don't seem up to the job as it didn't work! I edited the Link.php, Tools.php and config file but wasn't sure if anything needed changing in the ProductController, so perhaps that's where the issue lies...
edit - Just realised it's the CategoryController file that needs editing, not ProductController of course. Unfortunately still not working so must be missing something?