switch resolution for animation

[Tok Tok]

I working on some camera movements with some changes in focus. I set the resolution to something low like 500x300 to make the feedback from the GPU's very quick. It would be really nice to have an option to switch on that when the user is scrubbing through the animation the resolution automatically goes down to make it much more smooth. Corona render has this right now (UHD cache) but it makes a very pixelated image, while fstorm keeps a decent resolution while playing so that would be even better.