Cool and thanks again for the good photos the project. Early on with the Goliath's I quit placing a hex hole at both ends of the screw for the reason you're describing. The hex hole was only at one end so that when you opened and closed the vise it would be right hand. I had comments that some wanted the hex hole at both ends so I went back to that. The easy fix and what was done with the early low profile dovetail vise was mark one end red and the other end blue.
If someone needs a custom jaw attachment out of metal let me know. The wood ones are easier to make up yourself. The below sets are available. They were made for the 30# Goliath and the turntable vise but they will also fit the smaller of the two threaded holes in the 90# Titan.