Is there some particular problem you are trying to solve? I found more than expected grungy oil film in my intake manifold at about 8500 miles, but reasoned it was to be expected in a port injected engine. Now I just do a spritz of carb cleaner into each port before the warm up run on each oil change and that seems to help keep things clean.
Looking at S&S's breather routing diagram (In their engine manual) shows a closed loop system, which I'm going to say they went to some length to design and specify to deal with the very large crankcase pressure variations in a very big twin. Opening that system to atmosphere would, I believe, create larger positive crankcase pressure spikes with resultant oil seal issues.
