Made a post about this before but it got ignored. XD right after the gorgon maze when you reach the teleporting platforms, look to your left. There is a cave that leads to an opening over looking the atheon door. When you go here the new teleporting platforms spawn that lead from the cave to the door, you dont have to block templar teleports. You can use these pads to reach the broken vex teleporter. Since it looks like where the 5th chest spawns, im guessing it has special requirements to spawn if there is a chest there. Most people wont care until someone actually finds something there though.