I think the motivation for wiring the controller into the wiring behind the fridge was simply for convenience. It sounds like they just tied into the connection between the 12V distribution system and the battery. My father's TT with dealer-installed solar was wired like that and I watched a dealer installation video and that is exactly how it was wired. So the existing wiring DOES lead directly to the battery; however, there is a long cable run and your system will experience voltage drop due to that length. Rewiring an independent connection from the existing controller location won't gain you anything unless you are going use fatter gauge wires to decrease the resistance from the long wire run. You have adequate panel wattage to provide you useful daily charging during boondocking, but if you don't camp like that then I don't think it is worth the effort to change anything. If you do boondock, I suggest relocating the controller to as close to the batteries as possible and then using fat gauge wiring between the controller and batteries. If the controller can't be easily relocated, the using fat gauge wiring from its current location might be the best you can do.
Both inverters and solar charge controllers should have minimal wire runs with fat gauge wires to minimize voltage drops. Particularly inverters because depending on the size it could be drawing well over 100 amps. Both my solar controller and 1500 watt inverter are installed with about 5' each of positive and negative wire length. Solar controller uses 4 gauge wire, inverter uses 0 gauge. My inverter wiring should probably be fatter still, but I don't ever actually run it at max capacity so it hasn't been an issue.
