Ctrl+F2 through Ctrl+F4 launches the first three scripts in the file --> Run Script menu. Otherwise the developers have to make provision for shortcuts and such in their script by adding event listeners to intercept keyboard inputs, but that apparently has limitations.
Thanks for the response. I did get in touch with the developer, and he said as long as his script is sitting in the scripts folder ( C:\Program Files\Adobe\Adobe After Effects 2022\Support Files\Scripts\ ) rather than the Scripts\ScriptUI folder it should be detected.
I'm pasting screenshots for 1) what I get when navigating to Edit>Keyboard Shortcuts > type 'dup' into the search field to try to bring up the script 'True Layer Duplicator.jsxbin'; and what the developer gets (as did person who first posted a tutorial about his script). Neither of them had to edit any other files to make script available for shortcut.
Not sure if there's any other setting I need to toggle or tweak, or if I could have a conflict from one of the other scripts I have installed - but the script shows up for him and is trivial to assign a keyboard shortcut to, whereas I can't see it in my list, though it works fine through Kbar2.
My Edit>Keyboard Shortcuts search for 'dup'Developer's Edit>Shortcuts search for 'dup'