I'm using Saxon 10.3 to process an XSLT 3 stylesheet.

Using xsl:result-document inside the stylesheet called by the
transform() function, I get back a map entry in the map returned by
transform() where the key derives from the href attribute of
xsl:result-document.

So if I do something like:

<xsl:result-document href="/file1">
...
</xsl:result-document>

I get back "file:/file1" as the key value in the map returned by the
transform function.

Is there some way to get back a map entry with a key that doesn't have a
prepended scheme?  "file1" in this case?

https://www.saxonica.com/html/documentation/functions/saxon/analyze-uri.html
could help for Saxon PE or EE.