Ian, Brian,
the SeaRaider is not beamy enough to possibly offer any cabin comfort.
The BR is beamier and more multi-purpose. In particular, the BR is using it's aft length (incl. O/B well, mizzen mast positioning) much more economical than the SR, which I think already compensates for its being 2' shorter than SR.
I agree with what you write about the Hawk, Brian. The Drascombe Coaster is a similar case. Both boats are old designs, the Coaster goes back almost 30 years. I am optimistic one can do better today.
Novel option could be a raisable cockpit roof like in some campervans, and/or a different smaller 'foredeck' space, due to general use of jib furling gear from inside the cockpit.
As an analogy, also cars today make better use of limited space than they generally did 30 years ago.
C.