Not sure if my situation applies here, but my other toy is an air cooled VW that I installed a PCV system on. It also has a slinger instead of a crank seal. My logic was that there just would not be much air coming in through that drain back hole so I did not worry about it. I installed a vent with filtered air to the crankcase and a PCV valve on the oil filler cap. The filtered vent is 3/8 tube so is a lot bigger than the drain back hole. I sealed off the draft tube and it seems to work OK. I monitor pressure/vacuum in the crankcase and check for oil coming out past the slinger, no problems either way.
I did this modification to eliminate the regular drips that came from the draft tube and of course that has been eliminated. Some adjustment of idle mixture and rpm was needed, but no other changes. The point is, sometimes I can overthink things instead of just doing the project and seeing if it works.
