I duplicate them
Yeah I know you duplicate them, that's why I asked why you do it lol. So it's literally just for legibility reasons, was curious if it was for some other reason. For the lazy, like me, it's nice and easy to only need to add a letter to get it working.
Would it be possible to use a #base file for it though, and have the original kills set to how you have it and then have a new definition in the #base file? I don't even know if there's a point in doing that, especially if I'm completely misunderstanding how #base files work.