If they go back to FTL, how many former royals would want their own kingdoms back and what sort of new power struggles could arise? They could have Regina having to deal with no longer being the one in charge, because in their kingdom, power would most definitely swing back to Snowing, even if they don’t fully revert to the royal system. Regina would have to deal with that, and find her new role, because she wouldn’t want to go back to her former, exiled EQ role, but being back in that old familiar setting might tempt her. Re-building FTL is a process we really need to see play out, I’d hate for the show to just end with them all going back and we don’t get to see what happens next, but it’s not necessarily something that would qualify as blockbuster, super non-stop action packed storyline. So to see it play out gradually over a couple of seasons, with additional plot points like adventures involving other worlds as the main story, I think could work.
You make some really good points and I can see it playing out that the rebuilding of the EF may stop and start here and there. So 3.2 = The EF and maybe Ogres?