I love this Mod, but on the most maps with teleporters you can get stuck in other players easylie, even if theres a trigger_push to push the players out of the Teleport Destination Area, heres a Tutorial for a easy way to prevent this.
First off, you need a spawn room or some room where the teleporter is in (Incredible

Then you need the Teleporter, I think the best is a teleporter zone at the Ground with little walls around it, to prevent that more than one player enters the Teleport Zone at the same time.
MAKE SURE THAT ONLY ONE PLAYER FITS INTO THE TELEPORTER AREA (At least 32x32 units, a bit larger, but not 64x64 Units!)
Make a Teleporter Area at the Ground of the Teleporter Hole
Then you need the Teleporter Destination for this Teleporter on another Place on the Map, it dont have to be a Chamber like I did it, just be sure that a trigger_multiple Area (Reset Delay 0!) fits around it, a bit larger.
Now theres the Triggering Part!
Set the Outputs of the Trigger_multiple Zone to On Start Touch->Teleporter(whatever its name is)->Disable
and On End Touch All (be sure to choose EndTouchAll, not EndTouch!) ->Teleporter(whatever its name is)->Enable
For those of you who didnt understand this Tut, heres the Map file to take a look at it yourself!
If you have any questions, Post it here. I´ll post some more Useful Coop Tutorials soon,