If you have two adjacent chunks, collapsing one will impose constraints on the other one. Even if the RNG part is deterministic, as you suggested, the result will be different depending on which chunk you collapse first.
I don’t get it. If you have some location between two regions, and you fill it in starting from some regular point (say, centre of the south-west region), you will get the same tiling every time.
If you randomly choose a point to start at (like the player avatar’s current position), then I see that you might get different tilings when regenerating the location.
If you divide world into chunks and specify order of collapsing inside each chunk, and use deterministic random number generator seeded with the same thing for given chunk - then the result will be the same each time.
If you randomly choose a point to start at (like the player avatar’s current position), then I see that you might get different tilings when regenerating the location.