Sure. The compiling XSLT processors that I am aware of compile a
primary stylesheet with all included and imported stylesheets into a
single executable module. This module is then used to perform a
definite, specific transformation on any xml source document we want
to apply the  transformation to.

I have been discussing (in this list, I think) the high value of being
able to compile stylesheets that are not primary (such as containing
only xsl functions). Then there should be a standard mechanism for any
primary stylesheet to (link to) use the so compiled library of xsl
functions.

The other thing that would be really good is if calls to doc() using
references that are known at compile time are also compiled -
currently if you have a call to doc('config.xml') in your compiled
stylesheet and you run a transform 100 times then config.xml gets
fetched 100 times.