You are mistaken. It is not so much group knowledge that main dealers have, it is a set of detailed instructions from Audi on how to do each job. The parts to be fitted, the time it must take, the charge to the customer are all laid down. Knowledge plays no part in the process, and if their computer says no then all bets are off.
However if you as a non-mechanic prefer to believe the marketing nonsense put out by Audi I shall not try to dissuade you. If you ask your dealer what he recommends should be done at the same time as the cambelt I have no doubt he will be only too pleased to make suggestions.