Good Question: Why did Porsche..

[jaykay]

Well I purposely kept the old style in my sump, as I had heard of Cayman guys retro fitting the older style swirl pots to reduce foaming. Had holes put in my windage tray.

Sounds like change had something to do with engine placement. Perhaps oil return speed in the mid engine location was found to be dominant/more important than taking time to defoam. Perhaps foaming was found to be a predominantly rear engine problem .....something to do with the dynamics of the car