Fine, Hub-style, semantics...
Let's just say there are areas far larger than Emerald Vale with far sparser transition points.
Allow me to point out a logical inconsistency in your statement. You say you love that you can't save the game whenever you want, yet you're suggesting the use of autosave spots, which is essentially a means of saving the game whenever you want (if a tedious and restrictive one). So you're not advocating for the elimination of save-scumming, but rather for tedium?
In what ways would save-scumming lower difficulty in this game, especially if lets say you were restricted to one main save-slot on Supernova?
Well that's the thing, you're not forced to impose those artificial restrictions, you have the ability to choose to restrict your saves, and that's a good thing for an RPG. On the other hand, in the current system, I can't choose to save the game at my leisure, and that's not making things more difficult, it's just archaic and poor game design. As you said, I can always fast travel back to my ship, save, and then walk all the way back through all that empty space (because I killed/looted everything on this path already) to get back to where I was. It takes one out of the experience, but it's what one has to do in order to not loose hours of progress.