Anyone know what their simulation stack might be using? From the modest amount I know, mechanical engineering usually dislike their CAD tool and Ansys FEA simulations don't always converge. So how on earth are they simulating an entire aircraft with a single command?

When they say simulate, so they actually mean just using ideal mathematical models in Matlab?

I work in this space. Most likely it is a huge conglomeration of commercial CFD, FEA, and CAD softwares, custom in-house codes, and empirical aircraft design curves all stitched together with some python.