I like this line of thinking.
Dungeons with areas that move you to somewhere else in the dungeon (or even somewhere else) is a great D&D tradition. (There's an example in the three little brown books, Underworld and Wilderness Adventures, in the sample dungeon on page 4; transporters are mentioned in note 5 on page 5)
Not a bad design.
Who were last seen flying/floating up and away from the rift. Not seeing this one.
Ah, so somone else did notice it.
I like where you are headed with this line of inquiry.
IIRC, someone survived the original Tomb of Horrors by getting a herd of cattle and driving them before the party, triggering traps along the way ... not sure where I heard that, but it sounds like an old school way to deal with that death trap.