Question - when I did the revision of the C310 I noticed that the only way to make the “shape” (the green boxes that outline the components) fit the tail was to make the VTAIL area about double what the area is in real life. Did you find the same?
I still suspect, to this day, that the SDK may be incorrectly expecting us to enter the area of both sides of the tail (as if it were a 3D figure - which technically it is, but read on), summed together to get the corresponding “shape” of the VTAIL right. When in actuality, like the wings and Hstab, that value should only be entered once, as if it was one-sided (that is how those surfaces respond to the same values - two-dimensionally). So entering double the values of the VTAIL makes the SDK think it’s right, but man, that could be what makes the tail (and corresponding weathervaning effects) have way too much authority and stability. Thats before we even get to the rudder values.
At one point, I experimented with making the C310 tail the “book” area and it actually responded better to weathervaning (before the ground contact parameters were even introduced) as well as adverse yaw. I ended up doing what I presumed you did - made the tail area conform to the resulting graphical presentation of the SDK because that’s how they instruct us to do it. I’ve asked several times and have still never received an answer to that query.