Mojang now (by default) does not build datafixer rules on servers. LazyDFU continues to work as usual on the client and ensures that datafixer rules will not be built on the server, for consistency.
Improved compatibility with older and newer Minecraft versions: LazyDFU now supports Minecraft 1.14 through Minecraft 1.18 (as of this writing). Thanks to MrMangoHands for this contribution!