I'll second mlampert here. I'm thrilled to see some work in this area.
'Simulation' is one of those terms that's used to mean a bunch of different things so I'd welcome some discussion about exactly what you mean and the order/priority for developing parts of it. For example,
Simulating the movement of the cutter through the material (animation) is really useful to visualize the job operation order. As noted, it's quite resource intensive.
Simulating the resulting stock (like your screenshot) is also good for this. But if the shapes are accurate enough, they can also be used as input for refinement operations and detecting intersections with the model (gouging). That's much more important to me so I'd set it as higher priority.
Simulating the movement of the entire machine would just look really cool