Are config files and/or the PMF fonts architecture dependent ?
The PMF fonts are a variant of the PCF font format, they are (like the PCF format) architecture-independent. These fonts must be kept together with the other model config data since they depend on the printer model (de facto ${XPCONFIGDIR}/C/print/models/ (and/or ${XPCONFIGDIR}/${LANG}/print/models/) should be supplied by the printer vendors (but most people will create their own models on demand since I doubt that any vendor except HP, Sun and xprint.mozdev.org staff ever looked at that stuff)). Per definition they are read-only data supplied by the vendor, but modifying them may be usefull, too. I would say it is recommended to put treat all Xprint files in ${XPCONFIGDIR} as read-only vendor data; admins should create copies of this tree on demand (and/or (soft-)link some files) and set ${XPCONFIGDIR} to the modified config data.