One of the points raised is that the Yak in the sim is a SCALE version which does not necessarily reflect how an RC non-scale Yak will handle.
That's a key point, as Jim owns the only full size Yak 54 in the U.S, the original "Russian Thunder".... so he knows how the real thing flies.
That said many have pointed out as you have that torque roll authority is too low, and that is being looked at... I'll bet we'll see a new patch soon.