After blending my world, I see weird generation of big pillar-like formation at deeper caves. At least at deepslate caves, because I'm uncertain if this appears at stone levels. This weird generation may block a whole passage of a cave, big enough to cover it, but leaving tight spaces for the player to go trough. I don't know if this is part of the blending feature but I'm definitely sure generation like that is quite weird.

Seed: 89657966

Coords: 266 -18 24