"Unselect next" option has been added today to the reputation system, which allows players to cancel queued projects and slot them somewhere else, or save them for later.
I can understand Cryptic's concerns about allowing fleet leaders to cancel currently runnning fleet projects, but this option to remove the next queued project would be EXTREMELY useful for various reasons and I doubt would cause any harm at all.
For example, this would allow us to remove projects that were slotted accidently or prematurely, or the ones we intended to save for later. It would also help with projects that appear only after completing some other requirements.
So please, Cryptic, if it's possible (and I assume it is, looking at the Rep system), then consider such option for Fleet leaders.