IMO; leave the MB engineered system alone, it draws cold air, and flows many times the required volume.
The spewing air cleaner oil accumulator is frequently caused by the valve at the bottom of the return tube being plugged = drop the lower oil pan and clean it.
If you must alter it, use the 240D oil accumulator.


If you plug the crankcase vent:

* Oil fill cap gasket = if it is not fresh pliable rubber and does not seal perfectly against normal operating pressure = expect it to bubble/spit/spray.

* valve cover gasket = getting it to seal against normal operating pressure can be a challenge = I have seen the gasket do a Bronx cheer and start spitting oil (due to a pinched crankcase vent tube).

* front crank seal = many of us have 200K on it = less than perfect seal = expect it to leak.

* rear crank seal = many owners replace everything except the rear main seal = if it is the weakest seal = it can cause it to fail, possibly catastrophically = enjoy pulling the engine to replace it.

* vacuum pump to block gasket can fail due to this issue, but it is generally an easy repair + clean up the oil slime trails.

* injection pump gaskets, any one of these can fail = anything from minor weeping to a drooling/spitting catastrophe.

* the turbo oil return tube is a common leak point with a perfect operating crankcase vent, = I have seen a new grommet oozing/spitting (due to a capped off crankcase vent).

* valve cover elbow = many of us have 200K on it = less than perfect seal + brittle rubber = expect it to leak.

* the diaphragm in the shut-off vale on IP = three possible actions occur:
#1. On a perfectly sealed engine, the engine will start, then shutdown when pressure pushes the back of the vacuum diaphragm..
#2. On a partially sealed (leaking) engine, the engine will start, then run poorly/lack power when pressure pushes the back of the vacuum diaphragm..
#3. On a perfectly sealed engine with a BAD vacuum shutoff diaphragm, the engine will start, blow oil through the vacuum system, continue to build higher pressure (until something fails, relieving the pressure), and fail to shut off with the switch.

* lower oil pan gasket = if it is already weeping a tiny bit of oil = it can fail catastrophically = dumping most of your oil.

* head gasket = if it is already weeping a tiny bit of oil = it can fail = bubble/spit/spray.

* upper oil pan gasket = if it is already weeping a tiny bit of oil = it will make the issue worse.

*** intake valve guides = if they are worn + bad seals + excess crankcase pressure = the super saturated oil vapor can feed the cylinders enough oil/fuel to runaway...



Without service records and the exact mileage on the engine, I can only pass on (worst case) what I have seen happen in the field.