the deep tuttle was born with Formula boards when growing in width year by year.
55cm to 60cm was ok in normal tuttle boxes but longer sizes over 60cm started creating problems in the Formula boards.
I imagine the main reason for deep tuttle in Slalom boards is the lower weight compared to the normal tuttle box which has additional the two openings for screwing full laminated.
So dont worry to use up to 52cm normal tuttle! I never saw or heard about broken boxes except material defects.