Quite some time ago I’ve noticed Mesh.MeshData can almost read everything but not BlendShape data.
Very recently I had to deal with it again. Things were the same.
I feel like it is inefficient and incoherent. I personally use these on editor not runtime so it’s not that big problem. But it can be improved.
The Mesh team is actually doing a survey right now, if you wanted to leave them feedback. Also from wat I understand the roadmap is a decent place to leave feature requests as well! Survey forum thread