https://www.jabonipowerproducts.com/wp-content/uploads/2019/08/30A-MPPT-RVC_7.9.19-1.pdfThe max Voc input is 45v as noted. Usual advice is that the controller will fry if that is exceeded. That is a low limit for a controller. Many are at 100v.
You add the Vocs of panels in series and the 300w panel would already be about 40V (WAG), so no way to add another panel in series, only in parallel.
You put two 12v panels in series for say 45v total Voc in parallel with the 40v Voc panel and it didn't quite work. One thing is that the MPPT might have had trouble tracking with different Vmps of the two sets in parallel. Ideal is to parallel similar voltage panels.
So using the Jamboni set as OEM is a good idea. (You might have almost fried it, but got away with it being so close there)
Using two controllers on the battery bank to add their amps works with both set to the same Vabs. You can play with the adjustments on each to best match your battery charging spec for Vabs.
(I have two sets on the Class C with a PWM and an MPPT adding their amps. I had three sets but moved one over to the TC when we got that)
No idea for where to run the wires in your rig. I drilled a new hole in the roof and ran the wires down into a high cupboard and then on from there. Lots of Dicor to fill the hole in the roof. No problem. Big thing is find a good location for the controllers somewhere near the batteries. Wiring routes are all up to what your floor plan allows and what you can get at for drilling holes.
