Frustratingly, the reason for that is not that we aren’t trying (I have spent the last year, unpaid and in my spare time doing that) but that we made the most of everything that was available within the Flight_Model.cfg prior to initial release, much of which (the coefficients, the tables v speed) have been switched off by Asobo during successive Sim Updates.
We currently do not have the ability to take the flight model to the same depth aerodynamically without a massive amount of guesswork. The flight model as it currently stands is geometrically correct (the priority for MSFS) yet certain behaviours are incorrect. All the elements we used to make adjustments to what the core flight model decides is right have been removed, and the result is what you see.
The February update suggested that there will be further changes to the ‘legacy’ flight model in SU12, so there’s no point in further changes until once more we can actually see what these undocumented changes are. Why don’t we use CFD etc? If you saw how far from reality it takes the PA38, you’d not even ask. I know that there is a lot of movement behind the scenes on the core flight model, when Asobo give us a stable core flight model that gives us some long-term stability and allows the 3rd party devs proper control there may be a chance to get somewhere.