thx for your suggestions. I did already play with some of those parameters, but further tests are required...
Regarding the prop rpm gauge response, I was referring to the instantaneous response to the RPM lever adjustments in terms of the indicated prop RPM. It's perfectly in sync, on both ww2 aircraft. I believe their should be some lag, after all just like in the other prop aircraft like the Baron 58, even the Extra and the Pitts.
I believe this must be related to the "[PitchControl][Governor.Output]" configuration, but there is no specific info on these parameters in the Wiki at presente date.