Standard choice of fonts and font sizes would help with 4k displays.
Contrary to what some some admins say, there isn't any 4k support in v5x. I use windows magnifier to read the screens. To be able to select windows fonts, styles and sizes, would be a great fix. Icons would also need to be able to be resized. It's not trivial, but it is an inevitable necessity entailing some considerable rewriting. Sorry, but that is just the way it is.