Virgin tried this on with LHR and LGW until the CAA put a stop to it. They had to nominate one airport as the main base, chose LHR and all rosters have to reflect the report base. If pilots are operating a flight out of LGW their flight duty report time is at LHR and includes transport to LGW of 1 hour. Not such a big deal for most long haul flights except those two crew operations to Florida which use the Florida 2 agreement.
Pilots don't have to actually report at LHR if they are operating out of LGW but their flight duty period starts at the scheduled report time at LHR. Eg. LGW-BGI, STD 1000Z. Crew brief at LGW = STD -1:30 at 0830Z. Rostered flight duty report time 0730Z at LHR. Someone living closer to LGW just has to make sure that they report at LGW for the crew brief at 0830Z but their flight duty started at 0730Z.
Be interesting to see how long Jet2 are allowed to get away with that one. Anyone know who their CAA Flight Operations Inspector is?