Bonestorm frustration

I like the skill Bonestorm. I really do.

Would honestly like to know more about the interaction between bonestorm and psychic fragmentation. I don't think it actually works. And if it does it must be per-barrage and not per projectile which would make no sense since everything else is calculated per projectile on bonestorm so why not this?
Sure 12 extra projectiles on average would be insane, but aside from that it COULD effectively make casting faster and solve that issue, only it doesn't do that either.
If it is per barrage then the bonus is 32% chance to fire 20+2 projectiles effectively meaning you gain about 3% more damage in exchange for 5 passive nodes? Yeah very bad.
I know I could use scattershot to increase bonestorm cast-speed but if I wanted to do that I would simply use another skill as faster cast on a skill that hits 1 target in exchange for 30-50% less damage that inversely scales with levels and sacrifices a link slot is rather trash IMHO.