perhaps a if no one is occupying the room for 10 mins they lose their reservations? such as in a resteraunt
or! my second suggestion once a new team applies for the private room then the timer instantly goes down to 10 minutes IF no one is in the room. Yes both these Idea can still be spammed by the greedy but so can oca and fishing shouldn't be too bad
and at least with the 10 mins rule you always know you can get it in 10 mins (if you need the room) and it limits the amount of abuse (if your greedy ><)
Ice, Honor, Pride, HeRo...