Just to throw my
in here. C4S isn't a place where you need to worry immensely about the file size, the guys on there are going to download it anyway, not stream it. Yeah you don't want it to be huge, but spending ton's of time trying to get the smallest file that still looks good might be a waste of time that you don't need
I pump stuff out of PP back into original size and format so it goes pretty quickly, then fire the file up in handbrake where I have a dozen or so pre-sets that are good for everything from SD up to 4K, if your doing c4s I think you can still do like a full size and a mobile version so you get 2 bites at the apple still. Play around with a 1 minute video like what was suggested, and get your pre-sets down and you should be good to go.
mikesouth, if you've gotten a 20 min 4K video that looks good at a couple hundred MB, I'd love to see it and get the software and settings that you used, I've never been able to get them crunched down that small and keep them usable
