IMO there should be fuses in that collection of wires outside the battery box.
Here is a basic blurb on how you do "branch wire" fuses, to a buss bar, and then on, showing how the ampacity of the wires and fuses is cumulative. Ignore that this is related to car--it applies to RVs too.
IMO this is absolutely required where wires disappear into walls where you might not see them starting to melt.
http://www.bcae1.com/fuses.htm---If the existing solar controller only goes to 14.4 as noted, then you might want the controller that goes with the Trimetric 2030 you are getting, so you can perhaps set the Vabs to 14.8.
There is no reason you could not use the Iota, MeanWell, and solar all at the same time so they add their amps. The Iota will drop out of play 15 min after the batts get to 14.6, but then the MeanWell and solar will keep going if they are at the same voltage.
