Given the availability of Lithium Iron batteries at reasonable cost, I concluded that if the goal is to power fridge/electronics/lights/etc. it's MASSIVELY simpler just to get a Dometic PLB40 battery. (Note, that's for me - not looking to start a debate.) The thing is very well designed, simple, has a built-in charge controller, and really does everything needed.
I went with the Dometic because it's Lithium Iron not Lithium Ion, which means ~double the battery life & a discharge rate that doesn't decay as it ages. I believe Goal Zero etc. use Lithium Ion, so if you are planning a lot of use, compare.
The other thing I bought is a 130W
Bugout solar blanket. Because the Dometic has a built-in charge controller, it's simple. Plug it in and put the blanket in the sun and infinite energy. Done.
I have a wood platform in the back of the 4Runner, and am currently adapting it so there is a spot for the battery out of the way behind the fridge.
I thought about putting in a 2nd battery and wiring at the start, but the simplicity and reliability of this system won out.