Bike rack for electric bikes

[OneReallyOldGuy]

I’m sure there’s a thread on here somewhere about bike racks but I can’t figure out how to search past threads effectively, so here goes.
I’m thinking about buying a pair of electric bikes to haul around with us. We are full timers so they will “live” on the rear of my trailer. The combined weight of the bikes and a heavy duty rack will be about 250#. Plus I’ll probably have to get a hitch extension to clear the ladder.
Will the factory hitch support that kind of dead weight hanging 2 feet behind the trailer and does anyone know what the lever and fulcrum effect of 250# back there will be on the ride of my rig?
2 bikes plus a rack is going to push $5K so I really want to know what I’m getting into here.
Thanks, Phil
2019 39DBRS3