Cubdriver

This is a fascinating topic. I do not think sims are very good at predicting fully developed spins for a number of reasons-

1. They do not need to model it because few transport aircraft are certified for spins to begin with (none).
2. The cost of certifying the sim for spin dynamics would be significant.
3. Spin dynamics are very difficult to model, and even normal flight behaviors are tweaked using test pilots. How many of these pilots do you think are available to offer their opinion on how a given airliner behaves in a spin?

On the other hand, it is certainly possible to put some first-order spin dynamics into the sim for the sake of completeness. How accurate it is would be questionable. I also would not take very seriously any structural failures the sim claims in the spin, it can't make accurate analysis of stress in a flight regime that is largely guesswork and in this case is not even modeled to second order. It may be able to decide whether a wing is going to fall off in the recovery since that is similar to other actions, but the rest is not going to be very accurate past the entry phase of the spin.