Does this count?
About fifty years ago I owned a boat without stringers or bulkheads.
Hanimex 5.5 hp, on the plane (light load) and the entire floor would bounce up and down 3-4 inches. Even the bench seats were only glassed to the hull sides.

RR

the boats I’m talking about are the same type of construction only they are 30-45 feet long lol. They do take a piece of 2” pvc tubing cut it in half and glass that into the hull longways to give the floor a little back bone lol. It’s crazy I know.

Does sound a bit crazy.
Similar to here, boats up to 45’ long, most of the tour boats are plywood, have one central stringer runs all the way and bearers across the floor . They carry 40 people and get the job done but I wouldn’t want to be in one when the water gets nasty.

RR

They put foam stringers in these in part 2. Maybe you should show or tell the builders down there about this. It's all 3rd world looking building methods and materials.

"SQUIB" lol