hy, i cant help with specifics for your machine, since i am not familiar with it, but it should be possible
i just wished to ask if you can machine both radius without flipping the part ?
if at this moment you need to flip the part, then maybe you can solve this without probing, but by machining the lower radius, thus the one on the side that makes contact with your fixture; i don't know how relevant it was, since i don't know your setup / kindly