Go to the PHD area and there will be a square switch with a light above it (it may be red or green idk the full scope of the ee), then if the light is green, press F and it will spawn a drop in the air at 1 of the 3 jump pad spots that you fly by.

This button can be activated for me, seemingly every 2-3 mins, and this gives unlimited drops in the sky that NEVER despawn, so right now I have 4 Fire Sales and 2 Nukes stacked on each other in one jump pad spot.