Adding a Gravity Volume (Possibly a purple-looking Trigger Zone with an arrow to display the direction), upon entering said volume, the player would be swapped to be in the gravity direction from what the arrow indicates. This would either let players transition smoothly, which could cause some motion sickness, or with a comfort option, that would be toggleable in the Comfort Options.
Possible use cases: Anti-Gravity parts of a race, Stunt Runner course, etc.
PVP Games and Activities with Different Gravity Directions (Seeing a player be above you and upside down, etc.)
Hangouts, lots of futuristic rooms in my mind I could do with that tool.
Of course, this could come with a Reset Pin, upon triggering a Player ID, this player gets their direction reset to the normal one. (Could send a -1 after a game as an example)
Respawn Points could have an option to either care about the direction of gravity, or don't, which would reset it to normal if a player is in a different direction.