I would prefer that the core rules have the rules and not be setting specific. Instead of putting the the "things that aren't charted space" in a separate book, have a "You want to play in Charted Space? Here's the things that the setting uses" be the separate book. People buying the core rules shouldn't be limited by a particular setting's design decisions. The people playing in that setting should be the ones who need that clarification.Or maybe a separate supplement along with the warp drives etc. I'll use the rules they put in the core books, but if they make it clear they are setting specific it is easier to ignore (and to explain to players that all that stuff isn't true in this game).