Merlin - prop pitch, boost and mixture problems

[reflected]

I noticed that the coarser I set the propellor, the higher the boost goes without me touching the throttle.

Can somebody explain why? Is it accurate? I don't remember reading about this anywhere and it's not like this on the AccuSim FSX Spitfire either.

It's especially confusing knowing that it's not adviseable to use low RPM and high power because it's a big stress to the engine. But then, in order to lower the boost I have to throttle FAR back.

Also, I have a problem with weak mixture.
1) the lever animation is inverted.
2) I climbed up to 24,000 feet and set the mixture to weak (RPM below 2,600, Boost below +2) and my machine started shaking. Why? Is it that "weak" was too rich that high up, and auto rich was actually leaner? It worked fine at lwoer altitudes. Isn't it a bug?

Thanks!