Updating projects using the project generator

Is it possible to update an existing project using the project generator?

The project generator seems to be very useful, if I start a new project. But I would like to be able to add different addons to an existing project, without reconfiguring the whole project and readding all addons.

We could use a simple json/xml based cross-plattform config file, which the project generator can create, update or use to generate ide-specific projects.

I hardly use the project generator, i prefer working with the makefiles. So maybe I just missed this option.