I have XM819 rim, which are UST and basically the same rim used on the crossmax. Yes, you can use both of these setup. I personnally use standard (non-UST) hutchinson Python AirLight tires on these rims. I put some latex sealant in them to prevent them from leaking. About 60g per tire. I've noticed that the hutchinson keep the air as well as a tubed tire with this amount, way better than my previous Conti's explorer ProTection. Might be the 127tpi carcass, I don't know. Be aware that some people have had problem with burping as the beads of a standard tire do not fully grip the UST rim as well as a UST tire (obviously, they were not designed for this...!). I run 35psi in the rear, I'm 195lbs fully equipped, I ride mainly technical trails and I've never had a tire burp. I might be lucky. The weight reduction is so significant between a UST tire and a standard tire that this setup is well worth the try.