The main character of White Light was a math professor, closely modeled on me, and the setting was very much like Geneseo. The practice of writing science fiction about real life is what I came to call transrealism. In White Light, my life in Geneseo was the real part, and the trans part was that my character in the novel leaves his body and journeys to a land where Cantor’s infinities are as common as rocks and plants. — Rudy Rucker
Well, the transrealism word is probably not necessary as the concept, despite Rucker's repeated efforts, has never been clearly defined enough. I read that he's been trying to define this word since the early 90s.
Rucker kicks ass in writing both in fiction and science fiction. I have many books of his, both fic and nonfic, on my shelf and I compulsively come back and re-read them periodically. That means something.
He doesn't need to invent any new categories. Let someone else invent a word to describe him.
Rucker, dude, deal with it. You're a science fiction writer who happens to be a mathematician and popularizer of science. You've even written some software. Isn't that polymath enough for you? Isn't that sufficient?
That's my opinion as a long time fan.