Usually there is apocalypse, omegaverse, interstellar, ancient china, mermaids, entertainment world, Guide/Sentinel, Ger (in BL), medieval fantasy or modern school. Is there any other?
Xianxia/xuanhuan too. It may overlap with the ghosts/exorcists one, but there’s also that sort of yaoguai/demon one, where there are people that were originally something else (like an animal or a rock) and eventually cultivated a human form. I have seen omegaverse in one bg qt, but guide/sentinel seems to be fairly exclusive to bl (perhaps there is gl with it?).
modern setting definitely. Then modern can either be school themed, business, or entertainment circle.
I thought I'd have something to add but others got it covered. Can't think of any other. Maybe fairytale world, I've seen it a few times.
modern or western lore. or like legends of God's. also animals with human forms are fairly common in most qt genres
here https://forum.novelupdates.com/threads/chinese-world-hopping-novels-troupe.147527/ quick transmigration~ MC goes to multiple universe with different time, technology, culture and such~ usually with system that give them task to complete for reward~
Vampires , xianxia , Zombies/Apocolypse, School, Space , Anchient China/Imperial Harem. I've also seen Mafia stuff too