Tim,
It is true what you say about the "stay in the cockpit" technique. I have managed to master it for many years. I was able to survive a 30 km/h crash on my Lovelec almost unscathed because I stayed in the cockpit. Same with two recent falls on my Giant in Warsaw. If you must fall, stay in the cockpit. In my youth, I avoided very serious damage on my road-bike by staying on the bike, using clips at that time.
However, you do not need to fall at all. Many falls occur when the bike gets unexpectedly stopped. If that happens at the standstill, it is doable to let the bike fall down under you and you just jump over. That's impossible while clipped in. At least two times recently, I was able to avoid a crash by letting the bike fall down alone. I could see how it happens on my ride with "Mr Jagger" in Lublin. We were very slowly riding a crowded mall. Suddenly, Jagger had to stop to avoid riding into a pedestrian. Incidentally, he blocked the 203 mm front brake. I could see him "dancing" to avoid the fall. He would hit the ground if clipped in.
Another scenario is cornering in hard technical terrain (mud, for example). The rider would ride with the seat at least partly dropped and sometimes it is necessary to support the body with the extended leg, like in motocross. If you are an experienced rider, you clip out before. You don't need to think about it when riding spiked platform pedals.
You Ride On, too!