Never tried it either way, but what comes from that vent is excess oil and other contaminants. Not sure why OS bother with this method other than it would provide a draw on the case vent and ensure it exits. Personally I have no interest to run it through again, although technically it goes straight through the combustion process and back out again.
Tying it to the exhaust may be a better idea. I would recommend a second fitting to prevent that from getting back into the tank via the pressure line.
If you do go with a regular vent line to dump overboard you need to make it as short and/or as large an internal diameter as possible to allow that excess oil and contaminants to exit before the negative pressure as the piston rises from drawing it back in again.