I think there are ways that the battle system could be improved on without going to full tactical battles. I personally think that if fleet designs could be balanced in such a way similar to the missiles vs point defense, beams vs shields, ect, it could add a lot of depth.
For example a hit and run vs a heavy cruiser fleet. The cruiser fleet relies on overwhelming fire power to destroy it's foes, but is slow moving and mostly made up of medium, large, and huge ships. The hit and run fleet relies on small evasive ships that can dodge most shots, and have a way to get around the heavy fleets armor. Because battles are no longer all or nothing, the hit and run fleet can jump in do some damage and retreat with minimal losses and you could 'harass' larger ships.
You could further spice this up by using an idea I posted in discord:
I like the idea of weapon subclasses for example:
Railgun- Long range, can punch through armor, slow rate of fire, strong vs medium ships and above
Flak Cannons- Short range, fast firing, bounces off armor, strong vs tiny and small ships