Mnewbery, I asked Horsham Aviation about the Dynon transponder and according to them , its a grey area if it can be used at all. The transponder is TSO'd for sure, but it is controlled by a non - TSO'd Dynon Skyview. In some peoples eyes, this is not good enough.
Similarly there is the Skyview radio - based on the TSO'd Trig unit (who also did the Dynon transponder) - which is not TSO'd so cannot be used in controlled airspace.
The writing is on the wall that CASA is eventually going to be overwhelmed by a tidal wave of non TSO'd but demonstrably superior, and cheaper, avionics and will eventually have, with Airservices to relent and allow fitment and primary use.
In the meantime, since I don't want to d anything illegal, Im stuck with having to give panel space to a trig radio and transponder and to forget about ADSB - out.