Then it isn’t “stealthy” anymore and just becomes another mediocre performance fighter.
Which is exactly what the F-35 was designed to do. It is supposed to have 'first day of war' stealth, then become a follow-on high payload bomb truck.
It is not, and was never intended, to be an air superiority aircraft.
And I don't see the big deal developing a pylon that can hold three AMRAAMs. One triple pylon on each of four external stores stations, plus two in the bays, plus two AOM-9Xs on the outer stores stations is what the air to air "beast mode" requires.