Surprised no one has replied.
You might get away with using one but I do a little carpentry for DIY purposes and use a Black and Decker workmate similar to these.
Unless you stand on it and brace it with a knee it will walk around and the frame work will twist.
Basically you will have to bolt it down to the floor and weld in a load of bracing to make it rigid.
Better to buy some heavy timber and build a bench bolted to wall and floor then add a woodworking vice and a support. The heavier and more rigid the bench, the better it will be.