re injecting options and another question

Thx Vasil and Jeni,

I think we are all on the same page .... but I am struggling with
interpreting this bit of implicit behavior from the spec.

If anyone can point to the relevant area in spec are allowing for
implementator determined behavior e.g. injecting options, would be
great.

now for another option related question,

perhaps someday there will be an p:xquery2 and it will also have an

    allow-version-mismatch

attribute, and it will be part of official optional or required
step(lets say Xproc v2.0)

IT is unclear in Vasil example, and setting from commandline how XProc
would disambiguate options with the same names?

cheers, Jim Fuller