Would a wooden circle contact cemented onto the platform (possibly with rolling chair wheels or something similar bolted to the outter rim for support and continued rotation) make your platform more viable?
I don't know if this would personally work, but maybe try a swivel seat? I used to have one when I was younger, and it's just a thing that spins that you can sit on or stand on, in this case. It is generally used to help people get out of cars but as a small autistic child I liked spinning around very fast (thats why I had one lol) it would have to be done manually, So somebody would probably have to spin it for you. They can range in price, but I think they're about $30
The microwave edit is also totally doable without one of these platforms! I've seen a couple people who do the trend explain that they just rotate on their heels? I'd have to look into it further, but there are free alternatives! /lh /gen