Not the most photogenic mod, but here are a few to give the idea.
I bought a 30A extension cord and cut off the female end. I lowered the belly pan and fed the cut end through an existing hole in the floor up to the power box. The rest of the cable was laid inside the belly pan to exit at the nose. I notched the belly pan for an exit point. I can slide the cable in to keep it out of the way, or pull out to use it.
The transfer switch mounts to the back of the distribution panel. The black cord is shore power, the orange is generator. I used some of the orange to make the short feed from the switch to breaker panel.
I allotted enough of the orange cord when I cut it to have the molded female end exit under the rear bumper. It feeds through a hole in the bed, where I added a male connector.