I have a Class A CDL and must comply with the DOT rules and regs and it sucks, not doubt. I am not a more gov. kind of guy, that I can assure you, but this issue needs to be addressed.
With the continued increased capacity of these new HD pickups and the continued increase in the sizes of RVs, you are putting people with zero experience in trailering, in control of a vehicle way beyond their capability.
Personally I think at a certain weight or length or combo of both, it should require an additional endorsement, like a motorcycle license requires.
I don't worry about the bleed over from commercial to private. They will not require RVs to comply with commercial driving restrictions, Ports of entry could not handle that kind of volume in 100 years nor to they want to.
However, drivers should have at least a minimal amount of formal training before hooking up to 43' toyhauler. A day in the class room and a day or two practicing maneuvering a trailer is not a bad thing. Living close to Yellowstone, I see some crazy RV wrecks. Having the ability to buy a huge trailer or RV does not automatically assume that you can actually drive it safely.