No, when you run the Live Update, NOTHING will be added or changed in your %APPDATA% folders. Those are *your* modifications, and we never touch them when updating.
With several of our sceneries, we supply a custom .INI file in the scenery own folders, and these MIGHT be updated by a Live Update. However, there's a priority system and, if you have an .INI file for the same airport in the %APPDATA% folder, the one in %APPDATA% will take precedence, so the .INI file that comes with the scenery won't be read.
This means, depending on *when* you made the customizations that created your own .INI file and *when* and *if* we update OUR own .INI file during a Live Update, you might prefer the keep your .INI file or not, it's almost impossible to give an universal answer, because it depends on what you changed and what we changed.