@sylph_ Originally, the tracking was quite good. As I recall, the strength of the tracking is determined primarily by the projectile's turn rate (in degrees/sec), so simply reducing the turn rate to a very small number can produce interesting effects. For example, in a mod, I once made submarine cruise missiles track moving targets, but with a low turn rate. As such, they were useless against frigates, but effective against carriers and battleships, but a battleship could still dodge the missiles when microed to dodge or stop/accelerate repeatedly.
I think modifying MMLs to have limited tracking like this during the terminal phase - a lower turn rate of maybe 2 or 3 deg/sec - could make them more effective against large and slow-moving units, whilst still ineffective against small/fast units.
As an aside, an interesting note about limited tracking like this is that missiles which miss will tend to hit behind and to the side of the target. Increasing the missile damage radius could also help ensure that missiles which fail to impact the intended target nonetheless hit something else behind it.