Even though your idea of testing if both of variables don’t have the same content, IMHO we have a conceptual problem here of what means “adds new item” to a folder, since (in my point of view) a renamed file is not a new item … Note that I’m using the option “ignore partial or changing files” …
BTW, Keyboard Maestro is a wonderful software I’m planning to buy a license soon.
In renaming the file, the system probably removes it, changes the name and puts it back, hence it counts (as far as the system is concerned) as a new file.