Could the Revenge-class ships use small-tube boilers?
Short answerPossibly: a smaller, less cost-constrained batch could develop as improved Queen Elizabeths and reach 23 or 24 knots.
NotesThe scenario removes some pressure to build the largest possible number of inexpensive battleships. Five Revenge-class ships could consequently follow the Queen Elizabeth design more closely. Small-tube boilers become a plausible option for this later batch. A speed of 23 or 24 knots would bring their operational performance closer to the Queen Elizabeths, although that result remains conditional.