What crankcase breather setup are you using ?

The engine should not smoke.

It would be almost impossible for oil from inside the turbo, to make it to the inducer of the turbo, although it could make its way to the discharge of the turbo.

Plugs should not be black, clearly something needs tuned correctly.

what colour/smell is the smoke ? And no, even a new engine should not smoke, other than perhaps initial burn off some components like exhaust if they've been lying or had oily hands etc on them