I have these on my bike.
I have run 38mm Gravelking SK and Maxxis Rambler on them tubeless. No worries at all. I have beat the heck out of them and they're near perfect. Measuring 39 and 37.5 on my rims. Never a burp. If I had disc brakes, I'd try something wider but really it isn't a big deal.
I have Bitex hubs, Sapim Race spokes, and 3x 32 spoke lacing. I use rim brakes but they do make a disc version of the same thing.
My local shop sells them for $45. I've gotten 4. One to fix the rim on a bike I sold, one for a road wheel for my gravel bike, and 2 for the wheelset described. I think they're a bargain for what they offer.