The 1Up Super and Deluxe racks are RV rated... BUT... typical ebike is 50-70 lbs (and many are even heavier than that, things like RadWagon cargo bikes), rack is around 20-30 lbs, that's maybe 100 lbs hanging off your back bumper for ONE bike, thats going to very much unbalance a
Casita, and reduce your tongue
weight to below the minimum 10% of safe towing.
I carry two lightweight ebikes (45 lbs each) on the back of my 21 foot
escape, and I have to be very careful to put heavy stuff in the very front of the trailer to keep a minimum 450 lbs of tongue
weight (its a 4500 lb trailer). I'm also towing with a 6800 lb curb
weight long wheelbase diesel truck, which is extremely stable in the first place