Not sure if this is a bug or a trick, but it’s certainly interesting. I was just trying to reach the top side of the ladder in Ilaria’s shop, but in succeeding, I found a nice part of Sacrament with several houses that can be entered.
Requires Whittaker’s at III, but is otherwise repeatable. Only fell once on the way.
It’s also possible to enter the castle and unlock a shortcut to the water mill in Marin Woods in there.
Ive tried to make that jump before you uploaded this and i just fell to my death multiple times 