We have seeker missiles countermeasures available now in the 21st century, it is bit hard to believe they don't exist in 41st century so why not have this:

1. Small port countermeasures launcher that shoots seeker decoys

2. Capital turret countermeasures launcher that can be mounted on Tridents

When decoys are fired - 70% of seeker missiles turn to follow decoys and explode in their proximity.

Small port launcher:
Weight 600 kg
Ammo: 12 x 5 decoy rockets
Speed: 70 m/s
Detonation: proximity 50 m
Range: 1000 m
Lifetime: 30 sec.

Capital turret launcher:
Weight: 6.000 kg
Ammo: 120 x 5 decoy rockets
Speed: 70 m/s
Detonation: proximity 50 m
Range: 1000 m
Lifetime: 30 sec.

+1

+1 to countermeasures of some type that occupy a weapon port.

I don't like this implementation exactly though. The game already has a hard time checking collisions of missiles hitting much larger targets...

+1 knda. Dice roll on the sucess percentage.

More specific implementation of suggestions made before, but +1.

I would add there should be a Large Port variant too, which just has more ammo.

I'd just like it if shield turret projectiles triggered missile proximity fuses. That would make them a heck of a lot more useful. Right now you have to score a direct hit on the tiny missile and hope it doesn't decide that time was quantized in its favor and fly through the other side undetonated.