Belt drive, I don’t really see the point on a MTB where it’s having to deal with mud and grit. On the road, definately, but not off road.
Even if I wanted it though, it simply wouldn’t fit as the sprocket is much larger, meaning a larger (and wider) chainring too. There’s nowhere to fit it in!
No tyre buzz MArk, but then I haven’t been mashing uphill on it. I’m conscious of the Rohloff gearing being very low so I’m trying to spin uphill smoothly rather than than mashing a big gear.
It will be SS at some point, but 29+ rather than fat so there would need to be some major twisting going on to make that rub.