You kill the boss and immediately return to orbit to not lose the checkpoint and the drops go to your postmaster? But if you're too fast does the game save your drops? Or you pick up the drops first and as fast as possible and then return to orbit? You need to do the missions on hard?
Dude, do the Iron Tomb. Use 3oC, kill the first Iron Lord, use another 3oC, kill the second. Then get back to the bridge and jump. Repeat for profit.