Hi Roman,
AFAIK, my custom handler works with the latest firmware…
…BUT the latest HARDWARE version of the FGK-10x (aka FGDW-002) does NOT have the 3 internal connectors which were used in the FGK-10x to connect a local OR REMOTE DS18B20 chip.
Check the latest posts in this thread.
You may be able to find “old stock”, but in that case make sure you get the older "FGK-10x’ WITHOUT the built-in temperature sensor.
Sorry about that.