If somebody wants to help XSLT 3.0...

This open source Rust implementation needs more help of integrating the full XSLT 3.0 standard into their engine

https://github.com/Paligo/xee

So does every other open source XSLT implementation, along with XPath/XQuery 3x. Most of them at best support 2x or 1x with some 2x-compatible extensions, but I'm not aware of any that fully support the 3x variants, besides Xidel (XPath/XQuery 3.0). The proprietary Saxonica is the go-to at the moment.