Since the prices of solar panels has decreased so much over the years, there's not much point in spending the money, time and effort in trying to improve the existing system for only a few watts. For one thing, the wiring gauge will be too small for anything that's large enough for anything but trickle charging your battery while in storage.
IMHO, anything smaller than 100w probably isn't worth the effort. For example, Home Depot has 100w kits for under $200:
https://www.homedepot.com/b/Electric...1003,6620,6966
There's not much involved in "redesigning the system". It's pretty much limited to mounting the panel(s) and running wires to your battery, locating the new controller somewhere in between. Your new controller will provide all the monitoring you need so you'll be bypassing your power management system altogether. The solar LED on the panel won't light but the voltage readings will still be functional.
If your rig is similar to my 2002 Suncruiser 35U, routing the wiring down the refrigerator vent and down the back of the refrigerator compartment will give you a pretty direct route to your batteries with the controller located in-line at a convenient spot (kitchen cabinet above step well?). I've done this before on a TT and have two 160w panels to install on my 35U. I'll probably leave the pre-existing panel in place and just disconnect it.
In order to ensure both your house and coach batteries get charged via solar, I'd suggest installing either a two-bank controller or a Trik-L-Start.
There are plenty of online resources to help you with this. There's some good info here:
https://www.solar-electric.com/learning-center
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