I ran 2.1 Mezcals on my 2023 Crux. Super tight on the rear, and some very mild rubbing. While I really liked the feel when rolling straight on chunky gravel the steering wasn’t that great and it felt slow on pavement. I ended up running 45 Terra speeds since and they are great, although I lost some cushion. I have too many set of tires and other unnecessary items that I want to buy that I’m not buying any new tires until I really need them. I will most likely go with something in the 50mm spec when the time comes.
As for other bikes with larger tire clearance is concerned, I’d be looking at the Ari Shafer if I were in the market for new bike and the new crux wasn’t out yet. Somebody described the Shafer as pretty similar in spec to the Allied Able, but at a fraction of the cost. I think it’s a damn good-looking bike too, which doesn’t hurt.
I’m very happy with my ‘25 Crux despite the outdated tire clearance and I don’t think that is my limiting factor when it really comes down to it as far as performance goes. I’m working on fitness and riding technique to in order to get faster on the off road courses. All of my events are in California so it’s almost never muddy and usually courses are a hybrid of mtb trails and road.