These two mods (PANPC and SS2 ) are script heavy, which means the higher your FPS, the Fallout 4 script engine works more efficiently. More scripts don’t slow down FPS but they do depend on it’s value. To run more scripts per frame lets your game have higher FPS (for that you need a better PC than mine or use performance mods from Nexus)

I consider PANPC and SS2(before that SS1/SSC) to be the two most gamechanging mods on the entire Nexus for Fallout 4.