xsl 3.0 validation

I don't think this is actually a problem of this extension, I couldn't figure out though, if that's a Lemminx problem or if it's on Xerces' side. (I didn't find anything on xsl 3.0 in the Xerces documentation.)

I'm currently using a xsl stylesheet that is version 3.0. (The stylesheet can be found here.)

When I open the stylesheet in vs code, it complains about 84 errors. Most of them being things like: s4s-elt-invalid-content.1: The content of 'sequence-constructor-or-select' is invalid. Element 'assert' is invalid, misplaced, or occurs too often.
When I change the xsl version from version="3.0" to version="2.0", all error messages are gone and all seems fine.

This suggests to me, that there isn't actually a problem in the stylesheet, but much rather a problem with xsl 3.0 validation.

As I said in the beginning: I didn't find anything on whether or not Xerces even supports xsl 3.0. And therefore I'm not sure how difficult this might be to ensure validation of xsl 3.0 in lemminx or this extension respectively. But it would of course be nice.

Start with the linked menota_xslt_3.xsl stylesheet in VS Code and compare the diagnostics for XSLT versions 3.0 and 2.0. Investigate whether validation is provided by LemMinX or Xerces, then establish whether XSLT 3.0 is supported and what validation behavior should be considered complete.