Trees will attempt to generate even when unable to fit under world height limit.

[superfluke]

Specifically noticed with large oak, does not crash but only generates half a tree

[KandiPanda]

Ran across this post while reading up on this mod (thinking of trying it out to see what I can come up with), just thought I'd suggest that if a check is added to see if the tree will exceed the height limit, then the tree's bounding should be checked with something like (!world.isOutsideBuildHeight(blockpos)) rather that blindly hardcoding the height checks to 0 <= Y <= 255, for better compatability with expanded-height worlds such as those made using the Cubic Chunks mod (which can expand the build range to something like ±2^30 blocks rather than just the vanilla 0-255).