I don’t think matter can take an infinite number of forms. Atomic structure is bound by rules, and there are not infinite types of particles.

One way space-time can be curved is if time is circular — travel far enough and you are back at the beginning again. That implies a strange universe, forever repeating from the point view of a traveler but never changing in another sense..

I know, it’s weird. But possible. We just do not know and I’m not sure we ever can.