Wanted to confirm with the FT experts that I was given the correct info… looking to apply a GUC MC->PS to a DL-operated, AF-marketed 057 ticket stock for a flight in ~20h from CDG. While upgrade space is available, Diamond Rep mentioned that within 24h of departure, control of ticket is transferred to AF for all ex-CDG flights, therefore it is not possible to apply GUCs, same with flights ex-AMS; rule for all other departing airport is that GUC must be applied >3h before departure. Any other data points/confirmation of this rule?