Thanks for your thorough reply, Fafnir_6!
I wasn't sure if Casper was referring to your post in general or to just a specific part. It would be cool if anybody official could be a bit more specific.
I'm not sure if the engine is the real problem. Yes, it has it's limitations - the sonar was already mentioned. But if you know "the dark side" there is at least room for optimization.
Question is: Is it worth the effort? The stuff already added is stunning, but you can gather the resources largely at home. Try that with a Merlin- or Jumo-Engine. I guess it's much more effort, especially on the legal/financial side.
Well, anyway. I got so used to the IL2-Sounds and how to amplify them to the best outcome, I sure can live with the vanilla sounds.