Not sure what this is, but what is available via Loxone is the same as what is shown on that page you linked to. When I first ordered AroTHERM I was working on the assumption that the “Modbus Gateway” that was announced in 2020 would be available at some point.
See: New control units for more convenience – A new gateway for more control
There is some sort of Modbus gateway being used in some installations, but I can’t get Vaillant to give me any information on this, and my installer has also been successful in getting any details.
See Mark’s comment here: Vaillant AroTHERM heat pump group uk | I control heating from my Loxone home automation system (using the internet gateway and EEBUS) | Facebook
I should probably give up asking/waiting for Vaillant to provide something and go down the ebus route, but I didn’t get on the waiting list for the ebus hardware yet.