"Fallout Character Overhaul (FCO)" being a popular example of this). YOU need to know which "optional" components or "compatibility patches" are needed. (Often others than the original mod author will produce "compatibility patches" for additional mods. Be sure to seek them out by searching ...
there is no indicator. This is a fresh playthrough and I've been modding for a couple years now, so if anyone has an idea, I'm all ears.