Especially since we now have Frigate Escape Bays on every battleship, the Ship Maintenance Bay on the Nestor serves very little purpose. Make its 5000 m3 size a Fleet Hangar, thereby further strengthening its role as a support Battleship for prolonged stays in outer space.
It’s commonly used as an instantly accessible refitting tool for capitals, since you can refit off it immediately instead of waiting for the anchor time of a Mobile Depot. It’s got its uses and purpose, we don’t need to add anything more just because you don’t know how it’s used.
CCP could easily offer fitting service without maintenance bay if they wanted to. It was just convenient for then to give it a bare minimum bay to leverage existing functionality.
Also: Nestor is neither a transport nor a mothership, so no need for fleet hanger.