As noted above, you want the 30a plug up front, not a receptacle. Essentially an extension cord from the shore power plug at the back.
It is all about the rig's physical openings for opportunities to run that extension cord.
On ours with the cable box a the back, it could go from that cable hatch plugged into the shore power (although that cord would be coiled up which can make it run warm) down under the trailer to up front. It would be kept off the road by attaching it to the various items now attached to the underbelly along the way.
Then you need another extension cord with plug size adapters to go from there to the generator in the truck. That cord needs to be kept off the road same as the 7-pin cord.
When I tried running the Honda 3000 in the truck bed while driving, it kept conking out at odd times, but mostly ran. Had to kept an ear open for noticing if it was still running. Various theories why it kept conking out. Back draft vortex winds and oil level getting bounced being two.