I use QRhi for the shader pipeline in https://ossia.io which is a QWidget desktop app
Actually, the post also stated that using `QQuickWidget` will force OpenGL composition, so if an application uses QML inside QWidget it looks like QRhi will not be usable at all. It would seem that QWidget composition does not support QRhi.
top is your most classic QTreeView, bottom is the widget with content rendered through RHI (a preview of a shader effect)
I believe there is a reason why we don't call createWindowContainer with our use of QOpenGLWidget, though I currently can't remember it. If it still applies, then I suppose we might not be able to use QRhi.