Autominers actually never deplete deposits regardless of that setting because RE2 uses only voxel ore deposits.

As a historical note : in the vanilla game it was already so that autominers did not deplete deposits and even continued mining when deposits were depleted by hand/vehicle. So the autominers (and often large amounts of them) kept on mining although by then it wasnt possible to deploy new autominers there. Good practice thefefore was never to fully deplete the deposits to give others the chance to deploy their own autominer. However to battle depletion later on surface regeneration was implemented which not only restored the deposits but also the surface around the deposit which usually was covered by big holes from mining. The horrible sideeffect however was that this didnt go well with the autominers which disappeared. On approaching the map icon of the autominer was still visible but then disappeared accompanied by a message that the autominer had dsappeared. As the reason of this bug was unknown admins and their helpers started turning out replacements for the lost autominers which helped only temporary.