I think it would be helpful if Missions were persistent, pretty much like an ad-hoc temporary Squad.
It occured to me because of the number of times you see the ...ahem ... less experienced players crashing on takeoff or transit, or getting killed and reupping while the others in the mission are rearming. as soon as you die/ditch/land you get bounced from the mission which means you lose mission icon colour and mission vox channel, and with that the opportunity to learn from more experienced players.
It also means that the mission channel isnt used as much as it should be, because if anyone crashes on takeoff, everyone has to use range/room/country to communicate with others in the mission.
as a related wish I'd like to see the number of mission slots capped at 20% of the number on that country, to discourage persistent hordes, which would almost certainly be a consequence of the above ...