Emma

Worldgen stuff in Minecraft is a PITA, and this makes it substantially less so! Stuff like surface rule injections, feature/spawn injections, new feature types, and more recently biome injections are such versatile and useful tools for packdev. Granted Neo/Forge already has datadriven feature/spawn injections, this is still a must-have if you're doing anything worldgen related in a pack. If you're struggling with something, chances are that this will make your life easier.

This mod has been the source of many issues with other mods, such as entire recipe categories being nonfunctional, breaking HUD elements, and performance issues. Considering the alternatives to this mod (kubejs, normal datapack features), I cannot recommend use of this due to the glaring issues. Additionally, the GitHub repo seems to be archived atm, so I don't have too much hope for these issues to be addressed.