Power supplies? I'm so confused...?

Since all power supplies are voltage regulated there will never be an over voltage. A power supply can deliver up to its' maximum. It can only actually deliver whatever the system asks for. There are many tech departments where the staff are super trained in reading the answer sheet for customer questions, but have absolutely NO understanding of basic electricity. Any supply which does not see its' minimum rated load will not even kick in, as it actually needs its' minimum to do so.