Base owner's profit will lower too - maybe even beyond self-sufficiency level. Remember, Miner eats Reinforced Alloys, and it eats 4320 alloys/day. It also consumes 1 Mining Machinery per 20 seconds of mining (that's, again, 4320 MM/day). This means that the supply cost is at least 4320*250+4320*200=1,944,000 cr.
So, it should be much more profitable to preserve Machinery until night, when there's not many indie miners are in the field, and the drop rates are maximal.
However, maybe number of Miners in same field should be limited.
