With a very larger number of beacons in a single place, at the same time, you might start running into radio congestion/collision issues. This isn’t really an LTE-Beacon-specific problem, you’ll have it no matter how you want to detect the beacons. But if you set the advertising intervals high enough (1-2 seconds? somebody would need to do some collision-math to better estimate this), it should work.
There’s no ranging/monitoring in the LTE Beacon, ranging/monitoring are terms specific to the Core Location API on iOS to detect iBeacons. In the LTE Beacon, you just scan for Bluetooth data (any Bluetooth data, can be iBeacon, can be anything else), and you get scan results. I guess it’s somewhat similar to ranging in principle. You can read more on https://developer.estimote.com/lte-beacon/using-bluetooth/
Will the LTE beacon continuously scan the beacons for days
Sure, there are no limits (; You might need to plug the LTE Beacon in to external power via USB-C, because I’m not sure the battery will survive a few days of continuous Bluetooth scanning, although I think it might.