Slowmover everything you've said made sense, thank you. I also had never heard of insurance claims being denied, or people being ticketed for exceeding vehicle capacity in a private capacity; commercial operations are a whole different matter of course.
On the note of the Honda Odyssey: this makes sense. Before I knew about the extreme importance of aero I had a town and country, and with that same van I pulled a ~1,500 pound pop up camper which absolutely felt like it wasn't there. later I pulled a dunk tank which may have weight 200 lbs, though I doubt even that much, but was an aerodynamic horror, and the whole trip I had to run in direct drive and even then the van struggled. I've never made the connection before but with what you said now I know why the huge difference.
Now you've got me wanting to look for a more aero friendly camper that my current old holiday rambler that's a total brick, and just aerodynamically terrible in every way.