So this ini up there is not updated, I made some changes, I'll post a new engine.ini here, this part of the shadows, must be caused because I removed the screen effects like adaptive vision, bloom, and other effects, so I decided to return with these effects and focus on the scenery to reduce the view distance, and answering your question about the trees part, I don't recommend removing them completely because it gets in the way a lot when moving around the map, especially on a motorcycle, anyway. Here is an updated engine.ini. Any questions just let me know, my English is horrible if there is a typo, correct me.
Go back to post 366, scroll up and there are the graphics settings I use.