I'd love for there to be teleporter requirement options.
WHAT
In required mode, it would only teleport/activate/cast spell within its range if the required spell is present on the person triggering it.
In reverse, it could only teleport people who aren't in possession of a spell/buff.
Either would be fun, but both would really open up possibilities.
WHY
This adds logical switches to building up a phase, time restraints on puzzles using timed buffs, behaviour of the world that responds to the player. It means you can enforce that people need to find their way through the maze in 5 minutes or be teleported back to the entrance, or you can make a magical tower that uses teleporters instead of stairs, and players need a certain buff to reach the higher levels. Or you let them slip into the emerald dream to look for clues, but on a strict timer etc.
WHY NOT
It adds another layer of complexity to a feature that isn't the most used.
OPTIONAL
.unaura effects on teleporters, to level them up even more.