minor SPOILER
Bug of little consequence since fuel is of little concern by the time you get to Final Stand, but at first arriving at the Federation Base, you have a dialog which ends with command sending you off to fight the flagship and giving you 10 fuel for your troubles. (Hazard pay aint what it used to be.) If you leave that sector and return to it, it will give you the same dialog again and give you 10 more fuel. I'm assuming you could do this ad infinitum until the flagship shows up to spoil your fun, though I have no idea why you would want to.