Requiring blueprints would seem critical to actually being able to have a product to review for safety. Not only blueprints, but detailed material specs as well.
Nobody was asking for complete approval without blueprints. They just wanted an early indication along the lines of "sure, you're on the right track" or "don't waste your time, no way in hell we're approving anything like that." Or maybe "that sorta works but we would require X and Y," and then they could incorporate that into the design.
