Hello, thank you so much for this tool.
At first I did have an issue with the tool but it was specific to the avatar I was using (the Unity to FBX export caused issues with blender because of the root bone, no idea why).
So if anyone has such issues what worked for me was to export the Avatar as VRM then use the tool from this.
However I'd like to request a specific feature if it isn't too much work. The tool currently replaces all body types with the Avatar, however since I play in multiplayer with friends, I would prefer it if we could replace only one specific body type so that I would see myself with my Avatar and other people without.
Physics would of course be amazing if you are able to figure it out as well, still thank you for this.