If you enable the use of AUR in the pamac-GUI, it is that much easier to mix things up.
Some users could probably mix thiings up using pamac CLI (or downloading and building AUR package locally) that would not have any warning. but those users may be able to resolve issues from terminal response or copy/paste data in text format
But the better way to really mix things up is to install 2 or more AUR helpers
Recent topics about 3rd party AUR helpers show similar errors with pacman version for users on Stable branch
Any AUR helper should notify user if a repository package is being updated to an unsupported AUR package
