Don't ever recall hearing anything like you're describing, even after the remap turned the boost up. Is it still in warranty? Get it into Audi to be sure.
Mine has been bad over the last couple of weeks, went out with an Audi tech and they wanted it “urgently”.
But they also wanted permission to drive it as hard and fast for as long as they needed to, needless to say.. it hasn’t gone in. Coming from the same person who revved the nuts off of it in the workshop with a stone cold engine when I had the exhaust rattle which happened at idle.
It’s still bugging me, I’m pretty sure it’s not 100% but I’ve decided to wait until the car knows there is a problem. Any overboost, underboost etc it would flag up.. car pulls like a train, might just be sensitive ears.