Is it possible to use a datapack or mod for version 1.20.1, and is it possible to ask the author to add a mod or a datapack with support for this version?

A couple of the items in this pack use features that were added in newer versions, so a port that far back would lead to a lot of parity issues between it and the newer versions

If I get the spare time to do it eventually, I'll look into it more, but I won't give a timeframe or guarantee