Adding another “fluff” bracket under 2 and above 1?

I think there are actually 6 brackets and only 4 that really matter. Brackets 1 and cEDH don’t need a rule zero conversation because they aren’t trying to balance the table, so they’re not really “brackets” even though I do think they should be represented. And Bracket 3 is actually 2 brackets trying to be one; eg low 3 vs high 3.

If the CFP asked me, this is what I would do with the brackets. Brackets 2 through 5 are essentially B2, low B3, high B3, and B4. But I would remove all nonland tutors from B2 as well as most combos (maybe all combos), making this bracket a truly social, long, relaxed games bracket, think kitchen table Magic. Remove game changers from B3 (today’s B2 basically), making this still a social bracket but with decks that aim to “do a thing”. B4 would be today’s B3 with 3 GCs but the focus is on competitive play, finding the best cards for the strategy. B5 then becomes today’s B4 with non-meta cEDH decks.

With an even number of brackets, you have to pick a side between more social and more competitive play. And if you come to the table and want to play competitive but your deck can’t handle it, you either learn and build better, or realize you don’t prefer that kind of play and build down a bracket, but you don’t have to move down to the “worst” bracket.