Hi @BIGNEWY
It's difficult to find direct proper evidence, but I actually got some info that might be useful.
In the TAC-000 Harrier manual, which share many commonalities with the Hornet avionics, it explains in detail what happen when STEP is pressed. The Maverick circuitry is reset and the camera is boresighted, cancelling any lock that the missile may have at that point.
This is the current behavior of our hornet, so I would lend to think that current implementation is right and the F-16 may have some additional circuitry in the store management system to keep two missiles locked at the same time.
In fact, the manual also adds that the QTY value has no effect, and the missile can only be launched single
Best regards
amalahama's post in Mavericks don't remember lock state when STEP was marked as the answer