I was thinking about running additional charging cables and years of RVing brought first conclusion that you need to make a connector, who will unplug itself when pulled.
Regardless what age you are at- sooner or later you will have senior moment.
Than you want to make the cables the shortest possible, so logically would be to run them under cabin and enter truck box on front.
Maybe you can use drainage holes, but I would not hesitate to make holes and put cables into grommets.
My truck also has factory 400W inverter, so another option is to run 120V wire either for charging with camper converter, or at least use 120V for fridge element.
