I think this is the "best of both worlds" scenario. Min has displayed interest in Brittany and her behaviors are overall comparable to Max. Assuming Brittany isn't only interested in men, I could see her getting together with Min. Izzy got away with marrying more than one person and getting a happy ending that way, but I feel that that isn't what Max would want or should want; given he had an entire arc dedicated to getting his girlfriend back.
given previous comics, i think the implication is that in the rsf timeline max and cali WERE dating, but max fucked up somewhere along the way (assuming my "rsf has already diverged" theory holds water i'm willing to bet it was bc he never helped her during the rsf equivalent of volume 8) and they broke up, with him dating and marrying brittany some time after.
So, weird theory on the whole dating thing in RSF; I think that when future Max bound Min to the servitor, something went wrong, maybe Min really had gone fully unstable by that point, and that Min turned the tables and banished Max to the Sigil. Him "fucking up the relationship" with Calixta, and then marrying Brittany kind of screams so out of character for Max, but it could easily be the work of future Min pretending to be the real Max.
The riddler of the forbidden section certainly works out at the library…
(Wait, so does that mean Max started dating Britanny before Calixta in RSF or no?)
Did Key Manati just suddenly become another boring-ass country after the Queen died?