Notice how the lifters push their chest up? It helps with lifting in several ways but it also keeps the bar higher than the safety "catchers" on the side. Lie flat on your back and these catchers are above chest height and at all time they are above neck height.
The proposed technology would not really have saved the guy in the example clip.
Sadly most of the gym I've been to in my life don't use benches with those "side catchers" so it wouldn't be really useful in those case.
That aside, looks like a really cool project. I wish you guys best of luck