The closest thing Kerbal seems to have now to the edge shaders setting is "Highlight FX". Toggling it does nothing for this issue on my end. I don't see me rolling back drivers just for Kerbal. I would however like to try your script. I'm going to have to get back to you on that script. though. I just ran up on the notification that I had a response here, and I am a little worn out. Hopefully tomorrow morning I'll be more motivated.
It would seem a lot of people don't seem to be all that bothered by this bug, but it annoys the bejeezers out of me. LOL
P.S. Is it possible to just add those 4 entries into Steam in series? Or do I need to locate Kerbal in my .steam file and make the bash file to even use those? I ... didn't read the file. Sorry. Like I said, tired.