Thanks. I've had my newest car 12 years now and I wondered if 1.25" had become more universal since I last researched this. Looks like the answer is no. The 1.25" hitches on both my cars must be Class 2. Both are from U-Haul with labels 'lesser of 3,500 lbs or car's rated maximum'....use a 2" hitch receiver because it's more universally compatible with stuff that's out there, and there's very little cost difference.
Bolts are heavy, I think equal to an ancient Jeep Wagoneer. (Both around 4,000 lbs). I wonder if somebody braver than we've seen so far will try towing at least a 1,000 lb trailer with one. Stability should be ok but battery heating may force a very limited towing capacity. Has anyone related their towing experience?