I never really quite believed the oil drain back as a good solution.
Before I read Matt's comment, I had my mind set to a custom made bass restrictors of 1.6 to 1.7 mm and opening the returns on the heads.
Now After, I am confirmed my thinking is correct.
For oil upgrades in the head, I am still leaning towards a updated valve baffle plate, to help reduce oil in the blow-by gases. And further a oil catch can. If I decide to do a can, where can I recirculate back the oil to the engine?
Then, I been still trying to work on a oil pan baffling design that traps the oil, but has no mechanical moving parts. (Always been big fan of less moving parts, or total parts).