It would be extremely useful if a device dropping below a minimum specified battery level would trigger a notification to the administrator via email. This is a weak point with remotely located devices that are left on and accessible for long periods at a time. Even the genuine high wattage Apple chargers can require a power cycle after being left on for long periods, to avoid the device battery discharging faster than it is maintained.

Also would love to be able to receive notifications when a device's online status changes or if its reported GPS/location exits a certain specified geographic window.

Email notifications would be fine by me.

Would help greatly with tracking down lost/stolen devices without having to manually check SimpleMDM on an ongoing basis.