My truck doesn't have a camper package so it only has the plug at the rear of the truck.
I have tested using the rear plug and can only charge about 5A with everything off in the camper. When I use the fridge in DC mode, the circuit cannot provide the 10A necessary for the fridge, much less charge the battery at the same time.
I also tow a trailer on occasions so need a rear plug for it. Realize I could use a Y pigtail, but don't want to.
Plus, when I add the plug in the front of the bed for the camper, the run between the two batteries will be shortened, the wire gauge will be increased, and the connector will be heavier duty - all of which will increase charge rate.