If you have a 4k monitor then your sweet spot is going to be 2k (2560 by 1440). This will provide you with the best ratio between UI and gameplay.
The zoom is also not a problem as it is with 1k (1920 by 1080) where the maximum zoom is still fairly zoomed out.
You also have less pixelation at 2k compared to 1k on a 4k monitor and if you where experiencing slight stuttering (lagging) at 4k, this should also no longer be present.
As for the UI pixelation, UI is usually handled in a seperate pipeline compared to actual gameplay rendering, meaning the Vulkan API as amazing as it is, does have limitations. UI is something that needs to be changed manually and since this isn't a HD remake or Remaster but instead simply a legacy re-release it's something we have to accept. I'm sure modders will step up soon though.
