The problem with the 1080p resolution thing is that the UI and the overall zoom of the game looks too small, and it's clearly not the intended look. The UI looks blurry on 4K because it's rendered on a different "layer", but it's supposed to look like that with those proportions and not the tiny size the 1080p resolutions have at the moment (which is how it looked when you forced the resolution ingame to 1080p in the disk versions, but is not the intended look). It's not a "how it looks more correct to you" thing because they clearly modified the UI to be bigger and consistent for all resolutions except for 1080p (unintentional).
I agree with the problems you describe, but I believe they're two separate (though equally important) issues: one being the UI is tiny at 1080p and doesn't scale using Alt+Enter; the other being the full screen UI is blurry and glitchy at 4K, which is the issue I'm focusing on with this thread.
When I originally described my issue, I think I described the 1080p situation as the 'good' one primarily because it was not blurry/glitchy. I hadn't personally considered size issues with 1080p at the time, but I absolutely hear that many, including yourself, have valid problems with the 1080p UI and I agree that they also need to be addressed.
I saw in today's patch notes that they're investigating adding screen resolution as a menu option. I hope this would mean they're aware of and considering all the different issues we've raised for various resolutions.
