that's really interesting, maybe he was aiming at Ritchey with his huge fillets.
Those Serotta bb shells are pretty weird. Just thinking about the failures I have seen on seat tubes, I might make the lug go up the side of the seat tube. I don't recall ever having seen a down tube failure, but I think seat tube/bb failures are the single most common failure that I have seen.
I think that a straight shoreline on a top tube would probably okay, on a down tube, I think that would be a bad idea because all the cracks I have seen on the down tube just go straight around.