I think a warning in the chat whenever Auto Deconstruct removes the last drill could be useful. This would inform players that an ore patch has been depleted so that they can begin cleanup (remove remaining belts, power poles, beacons, train stations etc.), and that it might be necessary to start planning the next mining patch. This way, Auto Deconstruct could serve as a poor man's YARM, without the UPS penalty that YARM incurs.

This mod does not know about the existence of ore patches. It treats every miner individually. It would be more UPS penalty to search for nearby miners.

For this application, the vanilla solution is better. Connect a circuit wire from a miner near the middle of the patch (any will do, really) to a siren, and set the siren to alert when the reported ore reaches zero. The circuit-connected miner actually does read the contents of the entire patch so this will indicate when the entire patch is depleted.