Oddie23110 I am gonna take a guess here, and say that you are looking at the crew. Don't use the crew for a reference in performance when it comes to cosmofine - they are jerky because of decreased renders/second, because crew are actually one of the most intensive things in the game. Instead, look at your actual FPS (it can be enabled in misc settings), and test how well you can run large ships. Cosmofine making the game lag more is theoretically impossible, because it does literally nothing but reduction
On a separate note, what are your PC specs? If you have an unusually low CPU clock speed, and/or are running mods, that might explain it
