When you move around the 3D while using cycles it turns noise and quicky the noise goes away.
However rotating the view feels and its slower. why not make blender switch to Classic OpenGl Mode while navigating in 3D, as soon as you let go the noise reapears and starts to denoise the image.
Think he just means switch from Rendered viewport shading to e.g Solid while rotating. I’m not sure if it actually would speed things up. Try switching between the different modes… there’s like a second lag until everything has been redrawn…
A nice thing could be to just overlay the wireframe on top of the cycles preview render while rotating/moving in the viewport. That would make easier to navigate in a scene that take long time to converge…
I don’t personally find it that annoying as it is. To me the fact that you can even edit it at all while rendering is amazing. That said, Brecht already said he thinks he can squeeze quite a bit more speed out of it so I think this issue may fade quite a bit on it’s own.