All possible with what is there right now, I promise you. People focus on the wrong things. All of that stuff is totally outside the sim, and doesn’t require sim or SDK support specifically to create. In fact, that has been the case in FS2000, FSX, and P3D. There’s no special SDK support for fluid sims or engine heat soak or any of these specialty aircraft systems. That’s all just aircraft code. We already do advanced engine management with the CJ4 FADEC, such as correctly modeled flat rating.
There was a lot of third party input, but I think Microsoft expected a much bigger positive response to the new tech stack given its large advantages, especially as far as developer effort and time are concerned. It’s really fast to iterate on.
However, the third parties have kinda put a line in the sand and won’t move over, for the most part. So the complaints are about the legacy C++ part of the SDK, not about really anything else. So, when you hear “the SDK is incomplete and I can’t do X with it”, that really means “the legacy C++ side of the SDK is incomplete and we’ve decided not to move to the new technologies yet.”
I own the P3D PMDG 737NG. As far as things not currently possible on the legacy SDK side, the list is not very large, but potentially troublesome. Getting navdata from the sim is still a WIP, you wouldn’t be able to get the exact weather radar return as you would on the real thing. I’m struggling to think of other stuff, though. Someone who’s on that side might have a more comprehensive list.
-Matt