That is some cool stuff. It will be light and portable. I have made many frame fixtures but all were for specific production frames, not universal types. Can you do all wheel sizes?

I would not remove as much material for durability if nothing else.

Off topic, I have always thought thumbs like you have with a few extra degrees of articulation are cool. Perhaps it's a more evolved design. mine only bend 70 degrees or so at that knuckle.