Modeling a foiling cat would be extremely difficult actually. It is a much more dynamic system than a passenger plane, and more importantly much less studied. One of the biggest factors is that the crew weight is a large portion of the overall weight, and that is another dynamic component. Sure I could write the equations for level, steady flight based on a bunch of assumptions and approximations, but that wouldn't come close to acting as a vpp.

It may be possible with some of the high end modeling softwares, but it certainly isn't cost viable to use a software package like that for a rating.