It would be awesome if you could save stock as machined from a previos setup and apply it to a new setup.
For example if setup 1 machined the bottom of a part and then setup 2 machined the top of the part it would be great if you could simulate setup 1 with stock checked and removed and then apply that stock to setup 2 so you can see how the two machining operations tie together.
It would also be awesome if you could render your machined stock to get a better idea of visual surface finish.
Perhaps in the simulate window have an option to convert the machined stock to a solid body or probably even better a whole new component that you could then take into render to play with.