Hi Eric,
The most ideal way to achieve this is to create separate MOPZ entries for all systems as in this way the system picks up any difference in SP versions and add-ons.
However, your scenario is faced by most and copying and adapting the XML is the best workaround available as long as the new systems is true replica (in terms of SP/Kernel levels) of the one for which the XML was created for.
Hope this helps
Regards
Deepak