IPS should make ranged attacks into a standard ray-spell linear AOE with full penetration for the standard ray range, and then function as a normal attack past that.

What this would mean is that ranged attacks would hit targets in front AND behind your intended target for 30m or whatever the range is, but not accidentally penetrate to something way way behind that you didnt want to hit.

This would eliminate a lot of the need to have to manually target rearmost mobs as they dance around...you could just line up mobs visually and be assured of full penetration