I will say, I don't get why people feel a terrible need to shoehorn 5e FR cosmology (The Weave, Shadowfell/Feywild) into Dark Sun. Dark Sun is not FR, the core books present the FR cosmology as a starter set of assumptions because it hews closest to "classic fantasy" assumptions. The Grey is the Grey, the Black is the Black. I will say I like how 4e incorporated "the lands between the wind" for the feywild and some of the primordial/god lore as possible backgrounds, but Dark Sun is explicitly not a setting that's intended to feature great bouts of planar travel.