Sorry, but that is not correct, just checked the Installer of Tegel Professional (Zuerich will be the same), there you have the option to select the Destination of the Installpath after you have entered the eMail and Serial, see here the Button marked red:     Per default the installer will use the P3D Main folder to add the Addon into Ecosystem\Aerosoft subfolder.   But, as the install still use the Scenery-Library Methode to register the Addon, some parts (Effect