Just to add my two cents to the topic, I'm not sure splitting off the magnetometer is the best answer. I had a D-10 installed in my Pitts 12 (steel tube fuse), and had to install the remote magnetometer to get it to work. It took some experimenting to find a workable location in the fuse for the magnetometer. I upgraded to the Skyview system this summer and, not expecting any problems, put the ADAHRS unit in the same place as the remote magnetomer for the D10 used to be. Didn't work. I finally had to install it in the top of my baggage compartment which is all aluminum and far away from the metal tube structure. Perhaps the sensitivity of the ADAHRS to magnetic disturbances could be reduced somehow. Just a guess, but I think fuselages that are TIG (electric arc) welded may have more disturbed magnetic fields than fuselages that are O/A welded. I've built fuses both ways and seem to have more trouble swinging compasses, etc, with the TIG welded fuses.