https://bike.kaliprotectives.com/helmets/
But it's a tradeoff. Full-faced helmets give the helmet another point of leverage on which to break your neck. On the other hand they won't erase your face, which is nice.
Not to mention that they will breathe very very very poorly, though I'm a little unsure how these wavecell helmets will breathe. Like the Scott helmets, lots of tiny holes seems like not as good as big holes for airflow.
Motorcycles on the other hand consistently travel at 30+mph and regularly see sustained 55-80mph on the highway. It's not the same problem at all.
If your helmet is likely to encounter a 60mph impact you will design for that. Most likely that means your helmet will be stronger, which means it won't break away as easily at lower speeds. This means when your head will take more of the kinetic energy in a 15mph crash than it otherwise would. Not to mention that the helmet will be heavier, which means there's more momentum on impact which may affect the way forces get dissipated.
If you compare with downhill mountain biking that's a very tiny segment of the population. It's true that some downhill mountain bikers may use motocross helmets. That's not what the average bike helmet is for, and it's not what the average bike rider should be using.
Don't use a motorcycle helmet as a bike helmet.
https://crazybmxer.files.wordpress.com/2013/09/bmx-racing.jp... https://i1.wp.com/www.njmotocross.com/wp-content/uploads/201...
That'd be a miserable experience, motorcycle helmets aren't significantly vented and in my experience have substantial sweat-absorbing padding. They prioritize minimizing wind noise and expect much higher speeds than most bicycles encounter...