Wow, that's really cool, and using pool noodles (and building the jig!) as a cushion/suspension is kind of brilliant!
When I was a youngling, I would have
loved to have something like this in my house. I took two years (I think? it's been a few decades…) of gymnastics, jazz, and tap lessons, and I had to suffice with practicing in the yard and driveway, both of which were pretty horrible options all around. This custom build of yours looks like it should be a huge boon to the little lady's ballet practice.