I almost got stuck in that XL dungeon Mom glitch, but I luckily happened to have an Emperor tarot card which teleported me to the same room, but with a different boss, who then opened the next level as usual.
I had so many great attack upgrades too. Quad shot, split shot, had maximum damage by the fourth or fifth floor, etc
boomerang shot is horrible in general in my experience. have not once found a useful situation for it