Also worth noting that they have SES 3.4 AR disc now too. Similar rim profile to the 4.5 in a shallower wheel.
I was planning on going with the 4.5 when I got my 3.4, but I find the “tubeless only” thing super offputting. The tire choice is so limiting on the AR disc line that I’m still not sure how they’re so popular. Hell, ENVE even recommends against using the GP5000 tubeless. There are like 5 tires to choose from, which is pretty annoying if you ask me.