Seems like double the work to me. I am sure I can set my DTI faster than I could change to a drill rod and jog into place. The DTI I manually position 0.1 away from the left side of the vise jaw, then in 2 sweeps it's zeroed. I can align 3 vises in 5 minutes and know they are all within 0.0005 of square over their face.
I know it's probably trivial but rubbing/pushing the jaws/vise with another piece of metal seems destructive over time.
If I need multiple vises aligned together (which is rare) I clamp all three on the bar I pictured earlier in the thread and sweep from the first vise to the last and snug.
If you don't already have a quick adjustment mag holder I strongly recommend springing for one. Takes less than 30 seconds to install, position, tighten, and start sweeping.
Brian
WOT Designs