In fact, your thread had me searching for chest protectors online
The more safety gear, the better, IMHO. I see guys in MX gear and it worries me. Full leathers are huge, under-armor is good and not falling at all is best.
Though I am not sure what a MX style chest protector would have done for me in that event. I landed on my own folded up arm with enough force that it broke all my ribs (arm was fine), and two years later they are just now figuring out that I tore something in my shoulder and they are looking into that now. I should have figured... that crash ripped the stitching out and tore the leather from the middle of my right shoulder blade all the way up to the middle back of my neck! Pretty crazy. But, no rash at all.
Blunt force trauma is hard to prevent when hitting something hard like that. Road rash and twisting or crushing injuries are prevented nicely with good gear such as leathers, padding and good foot protection.
Wear everything you have if practicing hanging the rear out on pavement. AND, if you have time to think about it (you won't) letting it go ahead and low-side is 100 times better than hanging on and doing a high side getting off over the top.
Best to practice sliding around on a packed dirt road or lot. Rear end steps out much easier and at lower speeds. Plus with street tires on dirt, you rarely will ever get enough traction to have it hook up and high side you.
Just my thoughts.
