When will Usopp get another haki?

[Warmmedown]

Could he put haki on his projectiles and fire them? Has anyone ever put armament haki on something and had it stay on when they release contact?

Could he store his conqueror's haki in a dial? Or store Luffy's? Or actually fire conqueror's haki in a projectile. During battle he's worn out and his mind becomes one with the projectiles and he can use conqueror's haki like they're part of his body.

 

[SSJ2]

The Kuja tribe were able to infuse their arrows with Haki. He'd need to learn Armament Haki to be able to do this. The bottom tier Straw Hats feel so far behind the power curve right now it's hard to see this even mattering.