Honestly, I don’t even remember. It was something to do with minor differences in the cursor movements of specific commands.
Anyway, it’s been years, anything may have changed in the meantime. I should probably give it another go, those were simple nitpicks that I was too impatient to tolerate.
It is not different from how the previous shared libraries worked. I guess it’s there to stop cheaters from buying a single copy of the game and sharing it with throwaway accounts.