One crazy idea, though; why not make these battles multi-stage? Like:
Stage one: engage defense fleet.
Stage two: penetrate minefield under fighter attack.
Stage three: fight station, remaining defense fleet elements, etc.
It’d give battles more drama and eat CR clock without being just endless-seeming waves.
Not crazy at all. Instead, I say "YES PLEASE".
This would add a highly-relevant flavour of spice to the tactical stew. I would welcome the necessity of fighting consecutive,
classic "approach battles" on the way to getting to knife-duelling range of the battlestation itself. Fighting against fixed immobile fortifications
should be significantly different from Starsector's basic ship-vs-ship combat in thought-provoking ways that go beyond our expectations.
Just one concrete example of such, among many others:
Temporary blocking terrain - in the form of a few hulks of previously-destroyed attacker ships - would be a minor navigational hazard for the player's attacking ships while also providing some short-term cover against sniper fire coming from the battlestation. I would like to have to metaphorically thread the eye of the needle on my way to a VERY carefully-executed maybe-victory.
A look towards another example:
<a new hope>
(Attacking ships involuntarily bucking, yawing & losing some speed as they close in on the battlestation)
"We're passing through their
interdiction magnetic field; hold tight!"
</a new hope>
Currently holding additional suggestions in reserve...