dont think i ahve better benchmark than 40 minutes with CX.
perhaps just try to do it if possible at HKG, they wd probably assist u do so while u r lounging n the Wing!
but we are out of luck if in N.A.,
i do think believe the FL staff should handle this for u, by sending your ticket to the office, while u wait at the FL. make a suggestion to AA? i will second
i suppose in LHR, the ticketing/reservation counter inside the lounge can do this for u?