Both V & H hold adjustments may be necessary when swapping boards, but not so much with JAMMA boards in my experience (just occasionally).
V/H position on the other hand may need to be adjusted more often, but if your monitor has a remote board you can stash that in the control panel for easier access.
4-6 board switchers have been used in some nice setups, depending on your chassis, you just have to fiddle with the H/V position pots until you find a happy medium that works for all the games you have in the cab.