What your accomplishing is simply allowing the excess oil to be reclaimed. Every carbureted motor I have ever seen has the vent oriented in such a way that most of the condensed oil drains back into the crankcase(while gases are caught at a filter). You could/should put some fiberous filter material(think scouring pad, oil will still drain off of it) in the actual catch can so that by the time the vapor reaches the exit filter most vapor has condensed.
When you think about it, this problem has a lot to with how high up the vent is on our engine. If the vent came from say 6" down on the side of the head and had a vertical tube, gravity would take care of the rest. On V engines, the valve covers are usually lower in the bay. On a carbureted engine the section of the the intake air filter does double duty by catching what the vent filter media misses. Also consider how small in diameter our vent really is in comparison to most engines.
An interesting note is that lawn mower engines have the vent running inside the filter housing but somehow do not manage to totally gunk up the air path. Most of them have an "L" shaped vent tube and oil drains back down the wall of the tube.
Here's a thought...if the vent tube was drilled out of the side of the valve cover and replaced with a metal tube with an "L" shape from the inside, running down a safe portion of the head, all the vent air would be taken from a lower point in the engine rather than right over the cams and lifters(unarguably one of the most turbulent areas on the engine). Because the tube would pull air from lower down, the wall of the tubing itself would supress more of the oil vapor before it reaches the exit. Bends or turns in the piping as it ascends to the exit force more vapor to adhere to the walls of the tubing.
Another consideration is the diameter of the vent. Small diameter, more velocity to evacuate the same amount of air. Larger diameter, lower velocity(or several smaller vents dividing flow between them). More time for vapor to settle out.
