I'm out of my league here but here's my thinking - the crankcase vent doesn't go directly to the manifold but into the pipe between the air cleaner and the turbo. Same with gassers where the vent goes upstream of the throttle plate. No significant vacuum there. The potential relevant differences between a Diesel and gasser in this situation are airflow and crankcase pressure. I imagine airflow is about a wash for the same engine displacement since in either case it's the downward motion of a piston sucking in air, aided or not by a turbocharger. Same displacement, same airflow. As for crankcase pressure, I expect that a 20:1 CR means more pressure gets into the crankcase than with a 10:1 CR so you get more crankcase gunk into the intake tract with a Diesel... or maybe better to say that gunk builds faster.

I've lost track of the thread but I think your options are to run a hose down to the bottom of the engine bay or put an oil trap and route the gasses to the intake manifold. Seems like a matter of conscience more than anything else.

Sixto
95 S420
87 300SDL