Most modules have most effects configured.
If your machine does not allow the efficiency effect, then all modules that modify energy consumption (aka pretty much all of them) will not be allowed.
This person seems to be talking about the base game (or space age) mining drills, not AMS mining drills. I don't (deliberately) remove allowed module effects under any circumstances. But, I noticed that if a machine has no allowed_module property, it allows all modules. I actually set this to {} (and later {"quality"}) if nil and that causes the issue.