System position/time monitoring

I am wondering if the IFD series are capable of external monitoring?  I know a singular WAAS capable unit has internal monitoring via RAIM and GNSS constellation monitoring and augmentation via WAAS.  So my question is if a second IFD unit is installed or an ADS-B Out unit (with its own WAAS GPS electronics) is installed do these systems have the capability to monitor each other to identify a position/time mismatch and alert the aircrew that something is amiss?  If I have an ADS-B solution that provides the FIS-B and TIS-B information to the IFD and other display systems are there validation and position information signals that the IFD can read?  If it does get this kind of information does it message the operator that the ADS-B FIS-B/TIS-B info is OK or not OK? Is there a third party device that can monitor a number of GPS devices installed in the aircraft an trigger an annunciator if something is amiss?