I’m hoping WotC will get on board with using some near variant or the same variant of the bracket system to rank and pair Brawl decks.
Maybe you could lead by letting people publish their would be bracket number, even if this is meant as Brawl (and isn’t yet implemented). (This will also help to show players, they are indeed playing with game changers, are 5 colours, have a concise combo; all while trying to compare theirself to other bracket II decks.)
(I get 1v1 vs 4 player are different dynamics but when you read and digest what 4 player deck grading should be, this doesn’t feel that wrong to directly apply to 1v1 commander.)