A2A Missile load makes in the order of 5% difference vs unarmed, weight & drag included.
F-35 will still be the best manned BaI a/c for the foreseeable future,
when cost effectiveness is not accounted for,
but whomever thought F-35 will best 4.5 gen a/c in A2A will have to revise
their calculation even regardless of cost effectiveness.
That is, unless a much superior BVR missile comes into being.
the missile will require about five times the G capability of the target to complete a successful intercept.
-Robert L Shaw