Large base: Stays the same. Half points at half health.
Small base: half points when a ship suffers four damage. Non-regen ships are simple math. Regen ships need damage counters to place on card to keep track of damage suffered. Regen does NOT remove the counters.
Why? Limits the impact of small base point fortresses without punishing Tie Fighters or Z95's. Prevents regen point fortresses from never giving up points.
Maybe five damage but four seems like a sweet spot for me.