My latest change to Proportions:
Missile speed to 30!
Now the Capital Ship Missiles go straight for the target in one turn, as far as their range can go.
I ran a test with the Phong's Missile Destroyers.
I saw several improvements. With CSM III, range of 12, my PDC were able of destroy only half the number of missiles than with the original spped of 5. The problem is that the missile took 3 turns to fly the distance of 12, and allowed my PDCs to fire at least twice on every missile volley. With maximus fly speed the missile goes straight for the target in one turn, effectively cutting by half the chances of being shot down by PDCs.