Belated response -
The GPS module has only 4 wires, which, I presume, means that magnetic data is not sent to the Revo board. The connector at the module is a 6 pin connector, so I could probably cannibalize a couple of wires from another connector to add to the GPS bundle. There are a few issues that I anticipate in trying to do so:
1. I don't know how to extract the wires and their terminals from the tiny connectors without damaging them.
2. I don't know the pinout of the GPS module.
3. I was planning on using the Flexi port for OSD signals, so using it for mag data would preclude that option.
4. I use PWM signals from my receiver to the Revo, so the Flexi-IO port is not an option, unless I can figure out how to use PPM to free up the extra Flexi I/O pins.