I'm quite happy with 5 10s and pinned pedals. With that combination there's no need for cages for keeping a comfortable and efficient cadence between 98-102.
Reckon I would have to see that to believe it. 100 rpm is somewhat fast. Every 6 tenths of a second, your leg makes a full rotation on the pedals. Start your foot at 12 o'clock and pedal it around to the same 12 o'clock position in 6 tenths of a second. Pedaling 100 rpm on loose pedals is possible for a second or two, no problem. But pedaling 100 rpm on loose pedals for minutes or hours on end, In ancient times the racers used toeclips and straps for the advantage of pulling back and up while pedaling. But the clips and straps also kept their feet attached to the pedals when they pedaled at high rpms. Pedaling at high rpm and having your feet fly off the pedals is not something you want to happen in a close group of bikes on a road.