>> My assumption is that my Flarm data comes into the FX, is merged with the FX data from multiple sources and then wifi'd to the tablet. Is that the case?
That is correct.
>> My second question is can the data output port on the FX be configured independently to output satnav data generated by the FX, not the Flarm, which can then be connected to the transponder?
Unfortunately not, the GPS data is either INTERNAL(FX GPS Receiver) or EXTERNAL (FLARM GPS Receiver)
The reason for this is due to the number of internal UART's we can connect to the INTERNAL GPS OR the EXTERNAL FLARM unit.
If we connect to the internal GPS, then we cannot listen to the traffic being provided by the FLARM unit.
You will get the EiFi, and you can connect the output UART to the transponder - the source will be the FLARM unit though.