I would nerf it hard as it is overused to the point there’s no sense of not using it and minor WP cost won’t change anything. AP cost with skill to reduce it is what I would call a good start.
- It will nerf sniper rifles hard (1 shot per turn),
- Can be a good opening for making some of the body parts disablement lethal, like head for humans,
- Will reduce overall mobility and alpha striking (move a lot and don’t aim vs move a little and aim, it is large nerf to alpha striking damage per turn),
- Will make cover more relevant (you’re less likely to damage a covered enemy by shooting center of mass, aim to make a difference),
- Shooting off body parts will be more tactical option than guaranteed action (Arthron shield for example wouldn’t be minor annoyance anymore),
- Will focus more on getting close quarter combat if you want to shoot multiple times per turn instead of taking out everything from safe distance.
It would still be a great asset and game seller, but building a whole balance around it isn’t a way to go in my opinion.