We all already know that we can only have one timer box unlocking at a time. I've already suggested this to ATA devs, but I think having multiple timer box slots would be helpful to players and a bit profitable for ATA. For example, when we first start playing we get our free timer box slot as usual. Then, maybe when we've unlocked 16 or so many dorms, we get the chance to purchase a second slot for, oh, 15 ecs. At 32 dorms, we can purchase another slot for 30 ecs. Of course, most people stay at 32-36 dorms, but the incentive to unlock more timer box slots as you open more dorms could create a small profit for ATA, especially in seeing an influx of purchasing ecs or getting them through free offers. In the long run, this could make hunts more fun as it'll enable players to open multiple hunt boxes at a time and give more excitement to the hope you'll get something good.
I asked if ata would add more timer slots in this thread and this was the reply, so it seems like they are just looking for the right way to do it. Your idea seems interesting though, it seems like a good way to unlock more