I may be mentioning old news, but it looks like BA fuel surcharges vs what AA charges for the same award itinerary now negate out the $200 Chase credit based on some itinerary lookups, although it does not appear to apply for Y, just J (maybe F but didn't check that)

Examples (same flights/dates in all cases):

PHL-LHR nonstop r/t on BA in May 2023: $1768 in charges with AA miles for J, $1975 with BA miles.

JFK-LHR-FCO r/t on BA in May 2023: $1580 in charges with AA miles for J, $1783 with BA miles

Am I misremembering? I could have sworn that BA surcharges were essentially the same (give or take a little based on how partners did currency conversions) across all partners. I don't recall seeing this before, and interesting that it is almost the exact same amount as what one can get with the Chase credit.