I don't think that would be appropriate as even though you may miss the specific module that you're aiming at, you still are likely to hit the target otherwise.
No, your not as likely to hit at all if you aim for an external component at the edge of the hull (like engines or sensors), as if you had aimed for the CoM/Center of Area.
If we assume a random distribution around the target you are about 50% to 25% as likely to hit the target at all when aiming for a component at the edge of the hull ( depending on target shape ). Aiming for extruding things like a long antenna could be even worse where it's a very narrow target and a miss means missing the ship almost guaranteed.
Some examples of how it could work.
You have 50% hit chance with normal fire and opt to aim for engine that's 30% of the enemy size, this changes your chance to hit to be:
50%(base)*30%(size of target)*2(aim factor) = 30% chance to hit the engines instead of the normal 15%, but it's capped to 25% since chance to hit target at all is cut in half.
Same target but you aim for sensors that's 3% of the enemy size:
50%(base)*3%(size of target)*2(aim factor) = 3% chance to hit sensors instead of normal 1.5%, and you have 25-3=22% chance to hit another random part of the ship even if you fail to hit the small sensors.
I do like the idea of heat seeking missiles that go for the engines or power-plants however. Could make us see alot more boarding actions