Thank you very much for the report.
It is indeed not very clear and we will clarify and update the document.
That section of the telemetry manual was written before we added the two protocols F.Port Uninverted and Inverted to the Smart.Port protocol.
With standard F.port telemetry signal (Inverted: 0V=1, 3.3V=0) our flight controllers must invert both the input and output signal.
The Futaba digital temperature sensor adopting the S.Bus2 standard also uses a third Inverted signal (Inverted: 0V=1, 3.3V=0) but our flight control units cannot handle more than two inverted signals.
So, using the standard F.Port telemetry signal you will necessarily have to use the Jeti digital temperature sensor which uses an uninverted communication protocol (EX-Bus).
However, if you use a receiver with an uninverted F.Port telemetry signal (such as, for example, the Archer RS which has a special inverted output that inverting an inverted signal generates an uninverted signal, or by directly taking the uninverted signal from FrSky receivers as extensively explained on the OscarLiang site) then our flight controllers are able to read the inverted signal from the Futaba temperature sensor as well,
Obviously, in panel 3 "Receiver Selection" of the flight controller configuration Wizard, instead of selecting the protocol icon "F.Port/F.Port2 INVERTED (standard)" you will have to select the multiprotocol icon which as explained in the side instructions, among many other protocols also handles the F.Port uninverted protocol.
But, if you have yet to order the sensor, as explained in the manual, it is much better if you order the Jeti sensor because it has two separate temperature probes instead of only one and moreover it costs less than the Futaba one.
If used on a Nitro, be careful to order the Jeti 300 model and not the 150.