For me, a major concern with deck seating which is permanently fastened to the surface is it's ability allow a broom to clean the deck without fighting the supports and clearance.

Taking that into consideration, and the chance that kids (and adults) may at times desire to dance on the seat, the supports also need to be bomb proof. I believe I addressed those issues, while still giving the design a clean look, void of too many support features.

A bonus was the ability to use "drops" from the girders and joists instead of filling the dump with treated lumber, making for a happy landfill and a happier client.