Not sure if this belongs in this forum, so apologies if it needs to be moved!

Right now, I fly BOS/SFO - HKG roundtrip twice a year on CX, buying an R class ticket and upgrading into business using either my own miles or miles transferred to me by family members.

I'm considering switching to AAdvantage in the future now that MPC is transitioning to points instead of miles. I don't know if I'll fly enough to keep CX SL with the new structure, but it looks like I'll always qualify for AAdvantage Gold given my current travel patterns.

Is it possible to use my/my family's Asia Miles to upgrade to business, but have the mileage from the underlying R class ticket credit to AAdvantage? Do I go through with the booking as normal using my MPC/AM account, and then ask them to switch at check-in every time?