Your GCS version should always match your firmware version or you may have confusing results.
The firmware that fixes the east / west Naza GPS oscillation issue is exactly 16.09 Release, but with the aforementioned fix. It should be used with a 16.09 Release GCS, not a release candidate.
The fixed firmware UAVOs match the 16.09 release UAVOs so it is considered to be 16.09, but it is not built with the special RELEASE flag set, so it warns you that it is not a release on the firmware page. Any issues that you get with the fixed firmware should also occur in release 16.09 firmware.