I'm not sure why truck campers plug in at the front - it is a chicken and egg thing for me: The truck manufacturers first put the wiring up front causing camper manufacturers to put the plug-in outlet up front, or visa versa. Probably the front plug-in was selected so the rear trailer plug-in remained available...
My preference is to have the camper plug into the rear trailer outlet on the truck - it saves having to add wiring into the bed of the truck. Much simpler that way. Then where does the trailer plug in? Well, my Outfitter Apex 8 was designed and built by folks who really understand truck campers. The camper plugs into the truck's rear trailer outlet and then Outfitter provided an auxiliary outlet on the back of the camper to plug in the trailer. Simple but totally effective. Perhaps all campers should be made with this feature...?
Here are a couple of pictures of my Outfitter's connection features. The camper pig tail is on the left and plugs into the truck's rear trailer outlet. The auxiliary trailer outlet is to the right of the door. The red cables on the right are my dedicated high current camper battery charge lines - one positive and one negative. I already had 1/0 cabling run to the rear of the truck for my receiver mounted winch (and also run to the front receiver hitch), so I simply ran #2 gauge cabling into the the camper batteries and used Anderson Power Point connectors to plug them together. Many thanks to Cal Willis for his input and help in adding this feature to my camper. Terry
