I'm glad I didn't belong to this site years ago, when I drove - over time - two Karmann Ghias, one original VW, and two Corvairs. I know those VW engines were smaller in capacity, and didn't rev as highly, but I never once worried about 'more cooling air'.
I always figured the grills on the engine lids and the sealing tins were sufficient. Mainly, because that's the way the builders designed them, and I don't recall seeing too many air cooled cars back then over heating.
They were driven, and enjoyed, without me going to lengths to cut more holes, more openings, more grills.
I guess I was just stupid back then, and didn't realize what mistakes I was making...