It looks like the CO maintains a private GSAK macro that validates the challenge and currently they are mandating that everyone gets their approval before logging the cache as found. Therefore full CO cooperation would be required to create a Project GC checker. Hopefully they have defined the macro in terms of a set of polygons that might be able to be fed into one of the existing polygon checker scripts, otherwise a custom script may be required as a 'port' of their GSAK macro. Hopefully the CO could approve the Project GC checker so reducing the requirement for them to pre-screen qualification.
Do you know the CO well enough to ask them to help? If they have time they may even have the technical knowledge to write the checker themselves.
