I would also love this feature. It happens to me regularly that I’m trying to paste something into Obsidian and accidentally hitting ctrl C instead of ctrl V and being frustrated that when I do hit ctrl V I just get a duplicate of the line, rather than the thing I meant to copy. This feature has been an inconvenience to me often, and never helpful (it’s just too easy to select a whole line and copy it with a few keystrokes to ever rely on this), so I would love to be able to turn it off.
FWIW I think this is a duplicate of Option to disable Ctrl+C auto-copying entire line if nothing is selected, and instead do nothing