PR for this:
https://github.com/discourse/discourse/pull/7947
Screenshot:
The save category button will trigger the warning if the user changes one of the dropdowns and doesn’t click the plus button. They can click save again and it will ignore the pending change and save anyway. Clicking the plus button will reset the trigger, so if they don’t change the dropdowns after clicking the plus button, the warning won’t be triggered.
Also I changed the plus button color to primary so it stands out a bit more.
Does this sound OK?