Your boss is wrong!

I was holding L1 before, very clear of this.
Only L-1A can aviod LC application and direct file 140/485. L-1B and any H-1B are not allowed.
L-1A is manager title, also not an usual manager. Since you are not L1 visa, I won't talk this in detail.
L-1B is special technical professional, is not allowed to skip LC application.