I have ventured a bit in the End today and have some info that might as well be shared with everyone. The picture shows a funny generation bug at a Stronghold.
1777, -1555 are the coordinates for the Stronghold. There is some loot left there. 3 fully explored End Cities located at 3245, -285 / 4270, -580 / 4550, -1510. You’re lucky to even find a single shulker at those locations. Only 1 Elytra was found.
I didn’t check it well enough to say to be sure. It’s atleast easily below deepslate. There is a hole and stairs on surface to get down (and up) there that I’ve built.