Just to ad- I'm not a huge fan of vises. When I started out all my aluminum parts were made from big chunks of plate. Fixtures from the get go. When I started making smaller stuff I struggled with the "Buy thicker stock and turn 1/8" into chips on the flip". That 1/8" adds up and my cheapskate brain can't take it. So I'd do things like incorporate a heavy chamfer on one side or complicate the design of the part intentionally with two different profiles so the perimeter doesn't have to blend anywhere.
Previous to the expanding pins I was (and still am) using fixtures that flip onto bosses and use countersunk head SHCS in chamfers put in with reverse chamfer tools on op1 to hold them down. This is more complicated than the expanding pins. So I'm slowly moving that direction with many of my parts.
Many years ago previous life, I visited Airbus Filton as they were closing a couple of cells and the thoughts were "buy the cells and the work comes"....
The old horis had mostly one size fixture for a "rectangular plate" and every part was made from that size. So as you can imagine, there was a LOT of waste on all but the largest part.
I made comment to the guy showing us around who just shrugged as it wasn't his money....
Yes, I can see the whole "standardise mtl inventory, set-up reduction with quick changeover etc" philosophy, but sometimes, it's just plain lazy engineering....