A simple-ish way to resize the HUD to make it readable at 4K resolution is to double all the font sizes and double every number that is attached to x and y positions, height and width of elements, insets, gaps, etc. basically anything that has something to do with positioning or sizes. Not sure about 2K but I suppose multiplying all of the values by 1.5 should do. 8K should have all values multiplied by 4.

https://imgur.com/a/HQ3FbPo