One of the designs I have implement a woodworkers vise with the
approach you mention. I did add pins in front and in back of the tool
mount so the overall mount would be resistant to torsion and vertical
pressures. The tool mounts would be easy to build as they would be more
of a fabrication exercise than a machining effort.

The socket in the floor approach...that is something I wish I had done
when I poured my shop floor. I still may build such a system to be used
just outside the main entrance of the shop. When I get some time in the
future, I also may cut a hole in the floor and implement this
approach...very handy from what I have seen. So many projects...so
little time.

TMT