OK, that part became obvious.
But is there a way to use a KVO compliant class and have a
fullscreen display?
I mean in the Quartz Composer Programming Guide, the example given
to have a fullscreen display was to create a QCRenderer from an
OpenGL context and a composition file.
Is there a way to load the same composition file in a
QCPatchController? Or to make the controller know about the
QCRenderer?
Unfortunately, no, there is no way to connect a QCRenderer to a
QCPatchController.