Before the 16.23 update, modded beacons with productivity modules would effect machines they weren't supposed to. Some people thought this was a bug (even though you would need to use cheats for the beacons to accept the module in the first place). Others thought this was a nice work around to use productivity on machines that normally wouldn't allow them. And the 3rd group didn't see this as cheating at all, but a clever way to get around the limitations.
Stone/Coal/Iron/Copper/Uranium/Oil deposits are infinite and do not deplete. Mining speed is default, despite displayed yield over 100%. Oil extraction is dependant on richness of an oil field as in vanilla, however it will not drop below whatever yield it is found with.