I actually house rule that if another character is at the same location, we get to choose which character closes the location, which is what happens if a temporary closing situation comes up. More importantly there is currently very little incentive for characters to stay in the same location beyond healing and specific powers yet there are MANY location cards that interacts with multiple character per location. I personally belief it was meant to be a push your luck mechanism, stay together and risk AOE or seperate and avoid that. However it doesn't work if there are so little reasons to stay togther.