Currently there are, more or less, four roles. Which is fine for a four player game. But I feel like one more option would help serve the overarching narrative and the gameplay by better defining combat and non-combat choices for the players to make.
What comes to my mind as a suggestion would be Cyberwarfare. We are fighting machines, after all. I'm generally the mechanic of my ship, but when the combat first starts or we gain the upper hand in a firefight, I feel like I'm only standing around waiting for my friends to fail. If there were a way for a crewmember to throw out debuffs to enemy craft, I would feel more like I'm actively contributing to the firefight, rather than cleaning up after my pilot and gunner.
This may also address something I see in my playgroup, where we have a pilot, a gunner, a mechanic, and then some lunatic kamikazi launching themselves at enemy ships for little to no reason.