I cannot be the only one who is scared to move filled fuel tanks around when redesigning and cannot be bothered to pump it around.

Pressing either flush button for a booster fluid on a booster tank will cause that fluid to spill on the floor as canisters,
perfect for when you want to redesign and/or decomission a ship without the feeling of guilt that you spilled some drops. #environment

Any leftover fluid from flushing booster tanks is remembered and usable in future flushes (check with /se-cheepskate-booster-tank)