I have to concer with all of the above. We travel with DW's Pacesaver III. When we had a travel trailer had the lift on the bumper of the trailer with a box weighing less than the scooter, scooter was in the bed. Made a lunch stop and the bumper was about to come off the trailer. So don't haul the scooter on the trailer bumper.
We were also at GVWR of the truck with the scooter, two of us, and the trailer hitched.
We also went to the toy hauler. Now I carry an aluminum carrier in the bed of the truck that I put in the hitch on the truck after the fifth wheel is inhitched. Using this carrier makes my job of loading and unloading much easier and I don't have to mess with ramps, or taking the scooter apart, scooter is designed to come apart and be put in the trunk of a car.
Around home we have a power lift on the DW's Nissan Murano, had to add airbags inside the rear coil springs. Power lift is great like we use it but too heavy to make it portable, i.e. Move from one vehicle to another or from truck bed to hitch and back. I did fix/upgrade the bumper on the travel trailer and carried just the lift on it a couple of times but again too heavy to move to truck and back each time we moved on a trip.
Aluminum carrier is only about 50 lbs, maybe less as I don't use the ramp, sits between the tailgate and the fifth wheel hitch. Carrier has a 500 lbs carry capacity so more than enough for the scooter. Also gives me a way to haul scooter around town if we take the truck instead of DW's Murano. One other nice thing is that when this carrier is on the truck without the scooter on it the tailgate well open without hitting it. Allows putting stuff in the truck bed, close the tailgate then load the scooter.
Another thing to remember is any of the scooters are not weather proof so when hauling on a lift or in the bed of the truck a cover is required in case of rain. Also don't forget to tie the scooters to the lift, or when in the truck bed tie so they will not move and be damaged in a hard stop.