Hey, what's with the tone and the language here.
If you ask me, Captain certainly responds almost immediately, so I do not think that his team is a problem. Captain responds as quick as he can, well, as far as I know, their service is exceptional, and they do best to help provide our needs.
One thing you must understand, that no one else is experiencing the troubles you have, we all indeed experience the yaw instability, and rectify the problem accordingly (really it is not a problem, it is a fact of dynamics)
Why don't you do yourself a favor, try uninstalling the program, and reinstall it...that's the first step to a solution. If it still does not rectify the problem, and you're a little nice, I bet you anything Captain will give you another try at a download and reinstall fresh.
With that tone, whew! I'd be a little embarrased.

Just do that one thing, and reinstall it. Maybe it is your configs more that Captains software, I am not experiencing what you describe, other than that it does rock if you go too fast at certain altitudes. Another thing about this MiG, it was not a high altitude interceptor, it was more or less to get the target and get away quick, correct me if I am wrong.

If you want something supersonic, fly a MiG Flanker, MiG Fulcrum, or an American counterpart such as a Hornet, or there are others (but these are modern jets capable of these extreme speeds)

Tone down bud, we can help if you ask a little nicer.