Control heads is the main control module of the MMI system, but UK A6 only had the front control head (07).
Aux heater is an additional heater system that could be switched on remotely to warm the engine & cabin, again not an option in the UK market.
If options are switch on in the gateway you will just get errors, as everything requires hardware for it to work, there is noting in the gateway list that you will get for free by switching it on.
Mine has aux heater. Selectable in mmi. When on it allows the cabin to heat up quicker.