Genghis,
Quote: Firstly you are required to log brakes-off to brakes-on. Hobbs time logging is not correct or legal because you are logging time the engine is running but the aeroplane either hasn't started moving yet, or has stopped. If you are being charged by Hobbs, live with it, you still can't log all of that time.
That's a very confident statement on a perennial topic. Required by who? If there is any formal CAA guidance on this, I'd like to know. Many log Hobbs time as you are under control of the aircraft with the engine running. I think you'll find most hour builders with commercial ambitions will log Hobbs, especially if they're paying for Hobbs time.