I'm trying to think of a solution that isn't "hack Zeroing pz2 a dozen (or more) times and re-save with different names to get the zero poses you personally want" because that's some effort and requires some out-of-poser knowledge that you may or may not have. 

I guess the easiest way would be to get your pose "just about there" with PoseMagic and before you do any detail work that might not turn out after numerous dial-tweaking, just do a save on the pz3.  Proceed, and if you don't like what you've done just do a good old fashioned revert, which nowadays just takes a few seconds (almost as fast as digging up your library and fishing around for the pz2 you want.)

Oh, even quicker...same process but instead of save and revert, just memorize element and restore element which there are hot-keys for.  Super-speedy.