Engine On/Off is missing from Titanic and Furie for obvious reasons, and its presence probably makes little sense on large ships such as Vermaas, at least on those ships where the Old Man and the Chief are on speaking terms.
A|A, I think Terry’s use of “key†was generic for switch, button, etc.—vis. Telegraph Key. Vermaas, for instance has only buttons.
A lengthy, though lyrical, request for a feature that is visibly present should not necessarily be a cause for embarrassment—it happens occasionally, though usually from those who seldom, if ever, actually use the ships.