Yeah, but it is mentionned in the examples, that with the GM's approval, you can ''keep'' a point if you're planning on things like exceptionnal quality.
But nowhere does it mention that with PPs, nor any mention of having a ''Debt'' of -1 PP. (I guess the bottom line here depends on his you believe zero to be a limitant, or if you allow going into negative PPs.)
by RAW (and to be fair, its often flawed.) , and from what i gather you could get your magic rating of 6, get yourself some cheap datajack, drop to magic 5 in step 6, AND buy 6 pps in step 7...thus giving you an essence ''buffer'' to get more cyberware without losing essence of PPs n the future. -_-'
Of course,all with GM pproval, and not sure how that would pan out, especially ifyou ask him nicely for exceptionnal attribute before