sorry to tell you but this overcap on resistances is due to bad item balancing which doesnt require min / max anymore.
Stupid combos like Armor GA Harlequin just emphasize this “godly” balancing which is made for people who never play a game before.
In Diablo 2 there were mobs with auras that decrease resistance so that overcap was not completely useless (though almost never happened because of good item- / class balancing) …