I reecognize there are advantages to a 24V system but I'm not sure that this is an inherent advantage of a 24V system. Mine will be 12V and I will have a fused distribution panel on each side of the van. Yes, the wire from the battery to the panels will need to be a bit larger for 12V, but in my layout, those runs will be pretty short. No need for 2 converters. (... although it seems a small regulator will be needed anyway for the Maxair fan 🤷♀️).That is why I try to convince people to build 24 volt systems.
Put one 12 volt distribution / converter on each side of the van, near where the 12 volt is needed.
One wire pair from the 24 volt batteries to each 12 volt distribution box.
Run a few sort runs from the local distribution box to the point of use loads. Finished with electrical.