I'm not really happy either with the way the coordinates are stored in the xml-file. One approach to change the process definition from using the g-attribute to single attributes for each coordinate while maintaining backwards-compatibility would be to add these attributes while keeping the g-attribute. Maybe just for a certain time to allow proper migration. Of course this means redundancy. We could define the g-attribute being the relevant one in case there is in inconsistent process definition in which coordinates differ.
Just my 2 cents.