"You are the first in over 10 years I've ever seen make a comment about setting UTC per scene."
Well, I'll be the second one in 13 years then, to comment on this.
I find it very unintuitive, that it is visually a part of the Shadow dialog box, but isn't included in the scene settings under shadows.
I just stumbled onto this by mistake, but nearly did a sun/shadow-analysis with 5 or 10 scenes showing the shadows 1 hour wrong (DST). This might, worst case scenario, have resulted in lawsuits regarding loss of an hour of evening sun, as a result of a building being built on incorrect documentation.
Yes, I'll file a "feature" request..
Fredrik