Magnetic variation test inquiry

[Hakan]

My dear forum friends.

Is here anyone having a GPS close to a zero magnetic variation line and are willing to make me a small test.
I've a theory that no GPS in automatic variation mode will message a variation value less than 0.2 degree, plus or minus, and would like to have it tested.
The test can be done while crossing a zero line watching the NMEA signal, like the GPRMC, or why not record it using the VDR plugin.

The reason for my request is that my dated GPS, Garmin 120, no longer reports the variation. In automatic mode it reports 0.2 degree but I can manually force it to 000.
Now the fabulous Dashboard of OCPN can use the WMM plugin to make the true heading but only if the GPS variation is N/A, e.g. NAN. I've change my dashboard copy to do the same thing when the GPS variation is less then 0.1. It,s not a big problem to keep that updated on every new OCPN version coming from our team but if I can get rid of that it would be convenient. And also may I not be the only one having dated equipment. It could be that many of us using OCPN is not the folks buying the latest gadgets all the time?
If my theory happens to be correct It would be possible to implement my changes to the official OCPN Dashboard? And to a sufficient likelihood be convinced that we not force OCPN to use the theoretical WMM value instead of a possibly more accurate GPS value if the GPS would actually message a variation of 000.0 degrees.

I would greatly appreciate your participation.
Thanks Håkan