To be honestly, no one will use 3axis milling to mill your part.... that should be milled using 2.5 axis milling or 3D metal printer ( but I think it is too expensive atm ). Although AFR is powerful but I think your part is too difficult for it to handle. Sometimes, you just need to create sketches to help you finishing the job. As for AFR, it is only for 2.5axis milling, not for 3axis milling which is used to machine 3D shape ( so you need to select faces that you want to machine, but if you are going to machine whole part, just click that whole part icon. ) Another thing you have to consider is that if you have the tool to do the job? Some features just need special tools to machine... too many to consider..... so that is why 3D metal printer is so amazing