This video could be helpful for understanding some things. It doesn’t go into HDR as much as it should, but it does explain that our uscales usually use just one method, while the professionals use different upscaling methods per shot sometimes. So AotC/RotS would benefit from a professional upscale, not to mention the less-compression UHD provides AND wide color gamut.
https://www.engadget.com/2019/06/19/upscaled-uhd-4k-digital-intermediate-explainer/