The problem is not to control specifically HomePods volume or TV volume while playing content from the AppleTV. When the AppleTV detects I have Air Pods in my ears, it displays a notification and I can connect my AirPods to the Apple TV. Once the AirPods are connected to the AppleTV the Apple TV remote controls the sound played in the AirPods. I would like to replicate this behaviour with the Sofabaton X1

Unfortunately the repair from database was still broken in the new version. I managed to learn the commands from the harmony remote.

I have an update. I have taken my old harmony remote and I got it to learn the signal for power ON. To achieve this I wen to Devices > LG TV (the name I gave to my TV) > Edit > Add/repair key > POWER ON repair > Filter instructions from cloud data. I would then setup the harmony to learn. In the sofa baton app I chose the code 2/33, responded no, went back from 3/33 to 2/33 and repeated this until the harmony learned this POWER ON code. I can now use my old harmony to turn ON my LG TV, but the sofa baton X1 is still unable to remember the right code when I Press yes to 2/33

It is the LG OLED55CX

It is an LG55CX. When I try the 2nd code and I answer No to "does the device respond correctly POWER ON Key function" go back to the 2nd code try again when the TV is on it does not turn the TV off. Yet when I answer Yes the code is not saved and it looks like the previous code is still being used.

I have an LG OLED55CX

This is not a desirable solution. When I come to the living room and want to watch the Apple TV without disturbing anyone else in the house I simply press a button when the AirPods notification appears on screen and the AirPods are immediately connected to the Apple TV, I can then change the volume of the AirPods from the AppleTV remote. Something when my sons or my companion connected their AirPods.

It can be set up to turn off the TV in addition to stoping current video and turning off the signal on the Apple TV.

This is not correct. The power button when the Apple TV is connected to a PC monitor for example will stop the current video, and turn off the output signal of the Apple TV without turning off the monitor.

There is a power button on the Apple TV, please refer to: https://www.amazon.co.uk/Apple-MJFM3ZM-A-Siri-Remote/dp/B09365LQBK