My bench is 6í long but the workshop is only 8í long! So I am a bit restricted for movement when using the tail vice. Also, whenever I want to plane something on the bench between the dog and the tail stock, I seem to have to wind it almost the whole length back or forwards from the last setting, just the same with sash clamps - and how often it seems that once you have wound it, itís still short!
So this is a semipermanent bench planing accessory, and you can see that I can remove the plated screw to slide the stop forwards or back to one of 3 holes in the tail vice below. This is a lot quicker than winding the screw, especially as it is stiff and encumbered by a nail box and other stuff on top of a cupboard below. There are two steel pins in the bench which run in the planing stopís slots and there is a lip below the bench top to stop it rising under pressure.
Hope this is of interest.