Thought it was really elegant to lay out his 4 stanchions on a face plate and turn their outer arc all together, but I know I’d have trouble treating a faceplate as disposable - just make new holes to hold down whatever part you need. If I could get past this mental block of not wanting to ‘damage’ expensive parts, I think it would open a lot of possibilities.

He actually looks like he’s using an aluminum faceplate, and I can see where turning your own aluminum block to fit a back plate, then facing it every time you want to use it, like soft jaws, would be a decent compromise. Not as rigid as cast iron, but ‘just a hunk of aluminum’ when I would think about driiling holes into it.