I am going down teh rabbit hole on this one.
Boost controller it is. Fine.
Was ready to pull trigger, when I found this eco-worthy boost controller
Boost controller
It is small, cheap and good (it seems).
Challenge is, it only works with 12 or 24 v panels. Crap.
But eco-worthy makes a flexible, 130 watt 12 v panel.
130 watt panel
So my choice is to use the Amazon boost controller, along with one of my spare panels, and have to manu-fabricate mounting, move my flood lights, etc.
OR
Go with the eco-worthy solution, I believe I can mount 3 or 4 of those panels, in parallel on my SXS, and leave all my existing accessories alone. If I go this way, it would be 2 or 3 on the roof, and one or two on the side, or back windshield or whatever. Hence doing it parallel, so the different shading, etc should have minimal effect.