Cages for double straps, do they exist?

clipless pedals were around in the 70s though, no?

is their an advantage (aside from -weight) for the above racers to have partial grip coverage on drops/. all of them are doin' it and i see it on the street as well/? is it a rule/?

they only use the ends of their bars. and yeah only a few slip-on rubber grips are njs-approved