As a result of this, beyond 16,777,216 blocks, the fundamental shape of some of the things that generate appear slightly distorted. I've tried using the seed 102496288339226 to get a good side-by-side comparison, but I've flown for over 20k blocks and can't seem to get a good, obvious example. It's still clear to me that it happens though.

In vanilla, this affects ores and blocks that generate like ores do (https://bugs.mojang.com/browse/MC-185925; fixed in 1.16.2). Many Biome Bundle exclusive features appear to be similarly affected.

If we use FarLandsMod to push out the world border to the 32-bit limit, the effects become far, far more obvious. Here's some clay from a swamp around 200 million blocks out - note how they all generate in a line:

A desert over two billion blocks out, where all of the grass has been restricted to growing in a straight line:

I am not sure if these vines are affected, however they align with where mobs are spawned (https://bugs.mojang.com/browse/MC-167103):