removing scale animation curves

Hello!

We have a lot of character animation and a good deal of time spent int the animators update.
I figured that here animation curves are sampled/interpolated etc. and my idea was to remove all scale animation curves (as we don't use any scale anywhere) but I'm having some problems with that.

This is my code :
https://pastebin.com/PQzPirS2

This works but at the same time I now use a good deal more memory - does anybody know the reason for this?

I thought this might have to do with unity creating a copy of assets when changing something? I tried to put in this:

1. void OnPreprocessModel (){
2. ((ModelImporter)assetImporter).isReadable = false;

but that didn't change anything.

Happy about any suggestions!!
Seb