Starting to think about fitting the bath.   It's a free standing bath enclosed all round by it's own bath surround, which basically means it is a real PITA if you need to get at anything under the bath. So the plan is to avoid where possible anything that can "go wrong" under the bath, so first thing, pop up wastes are off the list.   So we want a reliable sturdy bath waste fitting that does not have mechanical linkages (hence ruling out a pop up)  The choices seem to be what