Ha! yes we don't have a framework for the multi-PI problem, something tells me it will be even more challenging...
Sorry for the confusion, and thanks for the question -- seems like a good note to have in an FAQ page.
Definitely recommend the 4b, I have been a bunch of 2GBs with no issue and would recommend them to start, might recommend more ram if you wanted to capture larger images but don't have benchmarking there.