Apple is now advising that you not reset SMC or PMU unnecessarily
they have also always had the same attitude with PRAM resets. I've never seen them cite a reason for this. They also say in several places to avoid resetting the pram/PMU/SMU/SMC while it's in the process of resetting. (you'll see them say press it ONCE and not a second time) I have no idea what they're trying to avoid/prevent.
