As Bruce has said it's all work in progress at the moment, but if you're happy to dive in here's some info which should get you started:

RFBee firmware: I suggest trying the master branch from my Github area, but you may have to try altering the baud rate to 74880 or 250000 to get sending to work OK. I'm sure I've got it to work on the default 115200, but I tested it again yesterday and had to change the baud rate to get sending to work. I've paused on further work on the firmware at the moment until some more hardware turns up, as I wasn't able to get to the bottom of some problems with *INCOMPLETE errors in some of the messages from HR80s. I hope to be able to do some more troubleshooting on these messages with my new toys in a few weeks.

Domoticz: I can't remember how far you got with your HGI80, but to use the RFBee in Domoticz you follow the approach on the Domoticz Evohome wiki for the HGI80 and add it as new hardware device. As you don't have an evohome controller, you probably won't get any devices appearing automatically in your devices list, but if you choose the 'All sensors' function from hardware page you should see your HR92s appear as temperature sensors. However, there's still a lot of work to do to get Domoticz working properly if you're not simply removing a controller from a working system and replacing it with an RFBee + Domoticz. If you were simply replacing an existing controller, the RFBee + Domoticz could just copy the device ID of the controller and all the device binding would still exist. In your case we're going to have to set-up all the device binding functions from scratch in Domoticz too. I think a far quicker solution that you'll be able to easily develop further yourself might be to use some Python scripts as these will be able to perform the device binding and programming.

I'll sketch out a Python script to get you started with device binding and setpoint control if this sounds OK to you? Once this is running OK, you might also be able to use Domoticz to at least monitor your HR9s until further functionality has been added to allow control.