I have changed the priority of Couatl64_MSFS.exe engine to HIGH and no more stutters at all, when switching camera views. As you can see, in my case, these stutters HAVE something to do with Couatl engine.
No, they don't.
Not in normal situations because, in normal situations, Windows is able to automatically allocate threads to different running process to the cpu cores that are less used, dynamically. This is of course done using the priority system, so the ones with an higher priority are given a preference over the one with a lower one.
If one or more applications in the system, not necessarily related to Flight sim, has forced itself to run with higher than normal priority ( this can be done with a Windows API call by the app itself ), and they are taking cpu time, applications with standard priority will of course suffer from this.
That's why it's wrong for an application that does not require running in high priority and was only required in your specific case, because something else was taking away all the Windows scheduler attention, to try to force itself automatically, like you are seem to suggest here.
What if EVERY application will start doing this ? It would make the priority completely worthless, since if everybody wants "high priority", you'll end up again with the same apps competing for the same resources again, making it even worse than already is for application that don't normally require it, and Couatl exe surely doesn't.
So, if I were you, instead of forcing Couatl running in a way it doesn't normally require, I would investigate which other application (again, not strictly flightsim-related) is taking so much cpu time that it caused that issue to begin with, chances are it might not something you need for MSFS, because this kind of behavior is more common from multimedia/audio/screen capture or similar.