I did ask about the double room restriction. The reason given was that guests have been disappointed with the space and bed size in those rooms, and lack of upgrade availability to give what was perhaps the Rome experience they had wanted given the price. To avoid that they recommend those rooms for single occupancy, but the FD staff I spoke to had not turned away couples turning up to use them.

Based on that I think they'd serve us better by adding the "Compact" declaration to those rooms as some other properties do, and letting buyer beware.