You definitely don't need accusim, 'external FDE' etc. to simulate propwash. It's a standard option in the airfile. I don't know why some designers don't use it. Of course you need a finely tuned basic FDE for this feature to work correctly.Concerning the tail-raising behavior, I believe A2A was able to get some kind of prop-wash modelled into their aircrafts. But since the simulator engine can't handle that, they are probably modelling it through the external Accusim module, then. Perhaps Milviz can implement some similar external module in future, which would allow them to model much more things the sim can't do ?