Thanks for the continued feedback and offering to help. A while ago I had a user share their config file with me but it completely matched mine, so I had no idea what was wrong.
I had another look at the game today and it turned out that it was indeed a global issue and I either didn't notice it earlier or it didn't occur for some reason.
I updated the mod to hopefully put this particular issue to rest - tested at all the listed resolutions again.
There are still a couple of unrelated imperfections I'm aware of and I might try to fix them in the future as well.
