I suspect Keyboard Maestro is launching a helper app, and the helper app says its scriptable. You should check with them if that’s the case, and if it really needs to be marked as scriptable – it may well not.
Firstly, I don’t have multiple copies of the app on my Mac and the one I do have is on my Mac’s system drive so I hope that answers those points.
I’ve done an awful lot of scripting work using SD with Keyboard Maestro and I’ve never seen this happen before. I don’t believe KM launches any other apps (helper or otherwise) and consists of just the KM Engine and the KM editor, as @ccstone points out, and both are AS scriptable. I really only noticed this 2 days ago when I opened up the dictionary window in SD to look at the Finder dictionary and there was the flickering.
I asked in this forum because I wondered if perhaps it was some kind display problem with SD given that things have been so well-behaved in the past - but that doesn’t seem likely now and given Chris’s comments I suspect it is just SD reflecting something going on with the KM editor app.
I think my next stop will be the Keyboard Maestro forum and if I find the cause I will post back here about it.
I’m replying to my own post here with an (embarrassing) explanation of what’s going on…
I had started preparing for posting my query on the KM forum so I thought I’d create a “better” screen recording and while doing so I noticed that my secondary display was showing a tiny thing - like a few pixels - in its bottom-right corner. After a struggle I managed to drag it into full view: it was a second KM editor window. KM allows you to have multiple editor windows open at once, but they don’t show in Activity Monitor and to be honest it’s not a feature I use; I guess I must have opened a second editor window sometime without realising it but I can’t explain why it appeared almost totally off-screen.
Anyway - closing the second editor window stopped the flickering effect and problem solved.
Apologies for wasting your time.
EDIT: Well, after going back and resuming my work with SD I notice that the “flickering” has returned. I am sure this is not an issue with SD but I’m also sure now that it is not to do with multiple KM editor windows either. The drawing board calls
Just for completeness sake, I identified the cause of the flickering: it is to do with certain features in Keyboard Maestro that cause some polling to occur. The response from KM’s developer was;
“Keyboard Maestro shows the results of the evaluation in the editor … which requires running an AppleScript to talk to Safari, which may result in some sort of interprocess communication process being launched, which is apparently what Script Debugger is seeing, since it is showing running processes.”