{SUGGESTION} Don't create the mkvtoolnix menu entry with the ending GUI in it
I agree that there are differences between the main package mkvtoolnix and the package called mkvtoolnix-gui, however I'd like to suggest that the menu entry being added to any start or program menu should be renamed to just mkvtoolnix.
The abbreviation GUI (Graphical User Interface) is difficult to understand for someone who hasn't installed mkvtoolnix before.
Note that I'm not TELLING you to change it, I'm just suggesting it.