The multitronic has known issues with the chain and input shaft bearing at higher mileages and both can present exactly as you’re describing before they become more serious. Your neighbour’s tensioner experience is genuinely encouraging because that’s one of the more common causes of this specific noise profile and it’s a contained repair when caught early. Getting a specialist who knows this unit specifically to do a proper fluid analysis and inspection tells you whether you’re dealing with that scenario or something further along.