Earlier today I, as well as someone else, had found out that the Doom's mines, as well as some projectiles (reaper, maybe) have full damage on the edge of the radius of their mines, meaning you could be out of what should be the closest damage radius, but still take full damage from them, as the explosion radius doesn't seem to match the visual radius of the explosion.
A viable solution to this would be to have the explosive damage radius somewhat match the visible explosive radius of the projectile, mines especially.
This would mean the mines do less damage-per-distance from the center of the explosion, also meaning they're less deadly the further from the core you get.
Alas, this would make the mines slightly less viable, since the explosion radius would have been adjusted, but if the Doom, and other minelayers were able to shut down the enemies engines, this would be a dangerous situatio for them.
The spawn radius for the mines shouldn't be changed, as a precaution to this. Changing the spawn radius for the mine to spawn closer to the enemy ship would be disastrous.