gamemode 10 (exclusive to bedrock edition, i don't know if they removed it, but, by changing the player nbt data to have gamemode 10, or any number that is not already a "real" gamemode, you get a weird mix of survival and creative, where i think you can fly, but you still have hearts, hunger and other stuff like that. I think they replaced it with spectator, tho)
I hate both the new one, and the old one. The new one is... janky... and the old one is unfair. The experimental versions of 1.14 seemed to fix the issues.. but..