Thank you, Mathijs, for the explanation. Maybe you are right that most customers just want to hear something they expect. Not something realistic.
I can only speak for myself, and I expect it realistic. But that's not the important point here, because - as you stated correctly - next to all customers have no experience in what is realistic in the crew deck. So I couldn't be disappointed by how unrealistic it is. I just wouldn't know. I have been on a Twin Otter, but only as a passenger.
The thing was, from the first flight to the last one (which was the second flight), that it was simply impossible for me to overhear all those technical shortcomings. It just felt like I was listening to an audio file playing in the background, unconnected to what happened in the simulator. It was the audio equivalent to a prop not being visually attached to the engine. Compared to that every mod, however unrealistic, is always better, as long as it's technically unsuspicious and somewhat "attached" to the plane.
Their seems to be an order of importance here: At first come the technical aspects ("Immersion", not "Disruption"), then it should be believable for the random person on the passenger seat. Then it should be realistic (not unimportant, but third priority). As I see it, Aerosoft has delivered only on the second priority. Now forstalling the first by chasing the third priority might not be the best tactic.
Having said all that, I am grateful that you are still willing to overcome whatever hurdles there are to create an "attached" AND realistic soundscape. There are a number of customers out there who are still patiently waiting ... and waiting ... 😉