If you book an AA flight on AA.com using your AAdvantage number and then want to change to use your QF number, my experience is oftent times they will add your QF number to the record, but it won't print out on your boarding pass, requiring you to manually submit your ticket and boarding pass for QF credit.

IME, When prompted, most AAgents just tell you" "your QF number is in there and don;t worry, you will get credit."

Well, we know from experience that if the QF number doesn't print out on your boarding pass, you won't get automatic credit.

Unless, AA has "made it easier in the last 6 months", I found a knowledgeable AAgent who gave me instructions to give a future ticketing or gate AAgent (or AC desk AAgent) to make the proper change as folllows:

"Add QF nyumber using Segment Select FFQF1234567 (insert your QF number there)."

I can't promise automatic results and don't know if this is truly different from how most AAgents would generally attempt this change, but it worked for me recently.