Sadly I can't get the miner to work underground. Using the mod with SE.
Regular miner in manual control works just fine as its supposed to.
The AI miner cant be remote controlled using the either the controllers or the unit controller and doesn't bore at all, even when driving yourself. It does pick up items on the floor when driving manually.
My remotes are working correctly, as are the routes, but there is another problem. For some reason, after he excavates the stone wall, no new one appears behind it and he becomes useless. I play without SE
I'm working on it. Seems like the path finder and AAI logic is too limited for this feature. It doesnt let me select waypoints outside the exposed underground area. Maybe I have to implement my own stuff (just command the miner to dig in one direction until it's inventory is full).
Since I never played with AAI Vehicles, I have no better idea.