Re: injecting options and parameters into XProc

let me try to explain the use case I would like;

I would like to be able to set option values via commandline e.g. this
allows the computing environment to set their own defaults at runtime.

one can set default values of p:option in declare-step but this means
the original xproc author is embedding how they see steps running (in
all environments); Xproc should be made easy to use by non-xproc folks
to execute.

cheers, Jim Fuller