DC-DC Converter or charger or isolated or non isolated...? Which one to use?

Our solar system on our RV consists of a 24V eco-worthy lifepo4 battery bank that originally was supposed to drive the 12v systems of the RV by the way of a Victron Orion Step-Down Converter but our system evolved when we decided to bring in a small Victron Charge controller so that we could utilize the tiny solar panel Forest River gives you in their Juice Pack system which meant I needed a small 12V battery on the 12v side of the down conversion.... I have struggled through a few problems trying to get my head around this whole change and came to realize that there are a few things to consider when choosing a step down converter.

I realize my theory on what was happening with regards to current directions and electrons ect is probably flawed however my thinking on changing equipment directions was sound. I still believe an isolated converter would have maintained the voltage level at a minimum set point similar to what the charger does in power supply mode but I do live having the added control over things with the charger. At the time of this video being published the new charger has been installed and is working exactly as I hoped for some time now.

As I've mentioned before I'm no electrical engineer but we are happy to have our install working really well finally.

[vmlinuxz]

I use an mppt solar controller to do 48v to 12v. Its pretty great, it takes very little parasitic draw to keep the 12v house batteries topped off. Those step down converters are a huge parasitic drain on the 48v system, and they are built like crap. Good mppt solar controllers intelligently stop pulling juice better when the 12v gets full. I think my mppt pulls like 1 or 2 watts once the 12v bank is full. I see no reason to ever not keep those batteries charged as they are thr batteries of last resort.

Im loooking at adding another 48v 100ah bringing me to 200ah batteries and 2kw solar. Currently im losing too much potential power during the day that could run the AC or whatever at night.