My 18x36 portable Hickory Valley module features Trix R1 (7 1/2") turnouts and some 8" radius curves. On that, I manage to run an Atlas shay, 2-6-0, Rapido 0-6-0 converted to a 2-6-0, 40' cars max with truck mounts. Rather reliable after decades of tweaking. But, I'd never go tighter than 9 3/4 again if I can help it, it's just too hard to modify so much equipment to get away with it. Be prepared to have to tweak just about everything, and also to realize that basically nothing wants to run slow speed when it's bound up on a curve that tight and on a turnout.
I'm doing Nn3 with Rokuhan 120mm curves and my Climax A, 25' log cars, 25' flats, and a 34' boxcar and that's pushing it right to the ragged edge too, but it actually works.