I hope you grip that better. That's very little holding power on the vise, it's liable to pull out. With that little purchase on the part, make sure you have a hinge in the other side so the jaws stay parallel.
Agree, I have parallels installed so the vice jaws stay parallel.
I have already successfully machined a few of these without issue. Taking very light passes.
I appreciate all the input. The material thinness, orientation of cutting forces and potential for stress cracking On a 90 degree corner have been discussed and the end-user is aware.
Sometimes artistic desires conflict with engineering and machining best practices. We do the best we can with the parameters given.