Why does everyone these days seem to think Billet is the go for everything.
Billet axles are the worst option for strength this side of Cut and weld.
All good axles are forged with no machining across the grain as happens with anything billet.

The only reason Billet anything is so popular is that CNC gear has become so cheap in the States and it is even cheaper to have made in China compared to Forged,It is all about the right material and most importantly the right grain structure in the metalurgy which basically means Billet is out and forged is in.

No Factory sports option stuff is anything but forged and that should tell you something,Billet is cheap to do to custom low volume applications and that is why they use it not because it is better.

Axles are the main safety aspect of many live axle conversions and that is the last place to cut corners,One does not want to look out the drivers window and see your rear wheel accelerate past the car.