Updating project file to new UE should not loose project settings

My project uses a number of external libraries which I added to the project file so they are compiled as well.
Whenever I update to a new UE version I have to add them all to the VS project file with the “add existing project” command.
It would be nice if the version update tool for the UE VS-file would keep the settings of the old project which do not belong to UE