Hello,
as in the title, I think that UHD Scale is set as a screen mode.
Good for save memory, but not the best solution for fly-through animation, because the sample size will change every frame.
I think that we need an option, like in V-Ray, as a World scale.
In V-Ray we have Light cache in Screen Scale and Word Scale.
“try to load + append” doesn’t solve every single situation.
Also, it will be good to have an option like in V-Ray: Don’t render final image.
It’s useful when you want to calculate ONLY the .uhd.