Does the oil cooler drain?

[Onex107]

I'm at 50 hours with my Aerovee and I don't return the blow by oil to the engine. I catch it in a seperator and dump it. The volume, per hour, gives me an indication of how the rings are breaking in, and my Cessna guru says it's a bad practice to return it because it's contaminated. But, managing the oil level, with that dip stick, is not easy.
My question is: Do you think the top oil cooler drains, when the plane is sitting, and gives a false indication of more on the dip stick? I haven't done the before and after running checks yet. Just asking.