Using Fabric Loader 0.11.6 and Fabric API 0.37.2-1.18_exp1.
Tested in 1.18-exp1 (Yeah it's compatible with 1.18-exp1).
You can make a temporary release for 1.18 as the mod is fully compatible with 1.18-exp1 and pretty stable.

I don't support any pre-release or snapshot version until it become release candidate or release version.

For this issue, I remove the hardcode part of the bottom of the world (before 0), but I didn't make sure it works in the snapshot or modified world. c7294d4
Also I added an item called Y-Setter, which can change the bottom of quarry area. You can set under 0.