Someone did that on a FAME/Hondo here but we did have to put a screw + solder on a common wire to ground all "grounds" together. Before I did that, it would sometimes act like a capacitor(dry night, indoor gig, walk on carpet) and build up a small internal charge and make a "pop" noise when the bass and I discharged across the gap(copper foil not connected correctly to ground). Took a while to figure out WTH was going on.