We've actually considered adding some guessing / helper features in the case that ADAHRS disagree, but there are many scenarios here, and figuring out truth gets tricky, even for a computer, in many situations. So while we do share that goal, we want to make sure any "guessing" we do doesn't lead you astray.
As for the network: At any given time, one of the DSAB channels is used for all SkyView Network device communications. If that network is unusable for any reason, the other is used and you're warned that you no longer have network redundancy. On the other hand, if an individual module fails, or if it is malfunctioning in a way that isn't communications-related, it's failure will not impact the other modules.
GPS is ONLY used for attitude aiding if airspeed were to fail. So an oscillating Garmin antenna wouldn't affect you attitude UNLESS you were already in a failure mode of not having airspeed. Although, all that said, we've heard of momentary position blips, but nothing so systemic that your GPS speed would be drastically affected in a way that would affect attitude aiding.
All that said, we'd recommend that your primary GPS source on a SkyView system - even if you have a third-party GPS - be either an SV-GPS-2020 (for systems that don't have a certified / ADS-B Out compliant position source in their certified IFR GPS navigators) or an SV-GPS-250 (for systems that do have such a position source on board). The SV-GPS sources provide multiple updates per second for SkyView and are known to provide a reliable GPS position that do not oscillate or otherwise misbehave.