OK. late to this thread, sorry. And of course, hoping someone on the LR team is reading ...
But I'm tiring of something which is extremely annoying, which is Lightroom finding a backup up copy of Photoshop CC that is buried 6 folders deep on a secondary drive which is a backup of my Laptop, and launching this instead of the copy that is located in the same folder as lightroom itself is on my Mac. Even if I have photoshop running, it will launch the wrong copy. I just don't get it, and have found no way to fix it. My solution (since I can't unmount the drive because it has stuff I use all the time) is to set the correct copy of Photoshop CC as the secondary editor.
OK easy enough, except now when I edit in PS CC, then save, Lightroom no longer automatically adds the resulting tiff file because it wasn't edited in primary editor. So I have to resync my folder in LR.
Oddly enough if I choose merge to pano the correct copy of PS launches.