Just did the PQs with a few friends. i think we know how it works now. The first clear seems to be guaranteed credit for everyone. after that it picks one random person in the party to give credit to. That includes people that already cleared. We figured out you can brute force the credit onto a specific person by having every other player leave that already has the thing done.
Lets say you have a party of people that looks like this:
Player 1 2/3
Player 2 2/3
Player 3 3/3
Before the boss at the end is killed, have Player 3 leave. that only leaves either Player 1 or 2 to get credit. Then reinvite player 3 and do the same again only this time also the other person that is now 3/3 leaves. That will max out the last player for that PQ.
