Ubiquiti isn't convinced the hacky mess of MongoDB they run won't corrupt itself when it hits a resource constraint on this device, and they also want to avoid RMAs when the controller either wears out the small amount of our device storage from too many writes, or when the whole unit bogs down from too many paired devices.
The controller should really be off board, or the on-board controller should be tuned to communicate less with the devices it s and write significantly less often to storage.