Progression to next level after mastery

This is perhaps a very paralysis by analysis question, but so be it...I understand that in the beginning you should test yourself for mastery and choose what week to start on (or to move on to next level) based on your results; however once you've found your appropriate starting point, say HBP/PE1 wk 9, and worked through the weeks until mastery do you start PE2 at wk1 no matter what or do you always test yourself for mastery after conquering the previous level?

Yes, your first workout with each new element will be a mastery test establishing the place to start.