So just bring the bag(s) to the counter, and hope they don't charge you?
Also, I asked already but didn't receive an answer, can AA gc's be used to pay the baggage fee?
According to the T&C's, no.
Gift Cards are redeemable toward the purchase of the base air fare and directly associated taxes, fees and charges that are collected as part of the fare calculation.
Gift Cards may not be used for products and/or services that are sold separately, such as upgrades; Admirals Club membership enrollments or One-Day Passes;
baggage fees; pet fees; unaccompanied minor fees; oxygen fees; ticketing fees for transactions processed through American Airlines Reservations; taxes, fees or charges payable in connection with AAdvantage® award travel; AmericanAirlines Vacations SM or non-flight products and/or services sold by American Airlines.