The answer is too ambiguous.RossDagley wrote:
This obviously implies all engine ancilleries (inc turbos, water pump you name it), the gearbox and clutch, the prop/drive shafts, diffs, etc etc.
You could infer in fact, anything that rotates or moves - driven by the engine.
You could argue that the engine runs the alternator which in turn charges the battery which in turn is able to supply power to the dash, radio, lights, blowers, windscreen wipers etc etc.
I think it's best to get the car serviced at an indy and if any issues arise that need urgent rectification like a replacement engine, you can get a replacement ECU. (If of course you claim on warranty through Audi)
Or you could just buy a 2nd ECU from Audi to start with and if there are any issues, swap it out for the standard one

Very very unlikely anything is going to go wrong to be fair, there's an RS6 with 1000hp and an RS7 with 1100hp running perfectly fine on the standard engines. A tune and an exhaust upto 750 should be well within tolerances.