Render smooth polygons is buggy. I have it disabled. I think it's linked to the edges file associated with a map, or lack thereof, in which case the map will use the default edge file. It can produce fuzzy shadows around polygons. A way to remedy it in a specific map is to use a transparent (empty) edges file. Turning "render smooth polygons" off "fixes" it, but only locally, of course.
Weather effects now make maps lag for me (never used to), so unfortunately I have to disable that, too. At least I still get to hear that soothing Soldat rain <3
You Got Urraka'd!