Hi Nicholas! You can get all relevant data via ebus, however the temperature sensors on Vaillant units can be problematic, which can lead to significant errors. See the thread here:
Electricity metering on the Vaillant units is highly accurate, so this only impacts heat measurements. I also have an arotherm 10 kW unit and am running a “hybrid” monitoring where I combine ebus measurements with my own temperature readings.
Depending on your technical skill level and - maybe more importantly - willingness to invest time, an independent heat meter would be the best option.