Why the quadruple 6-inch Town-class turret was abandoned

Would the quadruple 6-inch Town-class cruiser concept have worked on a hull unconstrained by treaty limits?

Yes, the mounting could have worked on its intended hull, but the Royal Navy decided that a quadruple turret was not worth the extra development effort.

The proposed quadruple 6-inch mounting could have worked on the Town-class hull intended to carry it. A larger hull unconstrained by treaty limits was therefore unnecessary to make the concept feasible. The Royal Navy abandoned the idea because the additional development effort was not considered worthwhile.