I installed the stable lift myself, which required a moderate amount of camper dismantling
Pretty much, the lock box is mounted on the drivers side, up towards the front. Since I had the heater/fridge removed for installation, it was really easy to run some heavy guage wire back to the batter box for the connections.
I'd imagine you could do the same thing with a fish tape and less dismantling.
Your plan sounds workable to me, but I'm not an electrician.
The only other thing to consider is that with a 4 jack system, It might be difficult to ascertain if all the jacks are operating equally if you can't roam around like when you have the remote. And, with the 4 jack system, using a remote helps to keep you out of the danger zone should something go wrong during the loading/unloading.
I'm guessing you've tried everything with the remote, but I'm wondering, is it a wired remote or a wireless? If it's wired, could it simply be something with the wiring between the remote and the camper? I know on my old happijac system, if the plugs didn't go in just right, things wouldn't work. Just wondering.