Ok so the DC DC converter has two output wires to the 12v DC panel, which is frame grounded, so anything using the frame as neg path works? Would it also work to just go from the DC DC output neg to frame and have just the pos wire?
The DC DC converter has 24v input, so it would go on the same batt posts as the inverter? (Mex would make busses there so there is only one wire per batt post)
Still true that it would be better to have the DC DC converter closer to the 12v panel, so the longer set of wires (the input) would be 24v instead of 12v? (for voltage drop)