I don't understand exactly what you mean, because PSCN already activates them and NSCN deactivates them. Doing both might get a little more complicated to have work (not in the code, I mean in the game)
Edit: oh, this is a tool. Maybe that makes more sense, it does sometimes get annoying having to use PSCN / NSCN to do it yourself, and for LCRY, I don't even know how to do that from the console. Something with tmp and / or tmp2 (and also probably life too)

In my mod, I have a different element also called ACTV (maybe needs a different name). It is sort of like SWCH, but you don't need to have SPRK selected to spark it with the brush, which fixes the problem of having to always change to SPRK. Also it can be turned on and off like SWCH, so you can make it unsparkable like when an electronic machine is calculating something, and then use PSCN to turn it back on when it's ok for the user to spark it again.