As I read it he is making irregular parts and has a hold down problem for the milling. His solution is to clamp a large plate to the machine bed, mill lots of them from one side, turn it over and mill the other side, then cut them free from the plate with wire EDM.

His problem is aligning to the plate when he turns it over. The two sides have to line up. Right now he cuts two reference edges and the top face which means he has to clean the whole machine down sparkly clean when he turns it over because the tiniest piece of crut is going to put him outside tolerance.

That is the way I would do it, but without the wire EDM. I can only plunge.

Of course I could be totally wrong