However it extends to any and all teleportation methods in TeleportService
The report was closed previously, but now earlier this year, running multiple instances for users with edit permissions in a game has been allowed, this behaviour should be looked in to and resolved (see An Update on Automated Action Against Modified Clients)
My current necessity for this (though multiple instances is useful all around) is to streamline my current workflow for testing replication across many clients, something otherwise offputting and cumbersome having to do in studio play simulations