Ah, that's a slightly different situation. VFDs don't like you switching between VFD and motor while they are live. This applies to the usual HY VFDs, for example. It means that you need a beefier VFD that is designed for online switching. I use a VFD to drive my lathe, but in that case I have permanently wired the VFD to the motor and use the VFD remote control connections for forward/reverse. With your combination machine sooner or later you are going to switch it "live" so you do need to check with the supplier that the VFD is designed for that situation. They are available - people with one VFD and multiple machines use them - but check first.