Dave,
Not sure which kind of tees C and A used. Someone needs to write a book about them! There were some C and A courses in Chicago, including Bob O Link, with an old aerial show here recently. I took a look at that old aerial and it appears he built two rectangular tees on most holes, longer than wide. That may not be universal, but its an example to start.
Potentially, rectangles could be quicker to mow, providing you design them in 7 foot widths to replicate the width of your tee mower (perhaps a bit less for overlap) meaning tees at 27, 34, or 41 feet wide. 34 foot wide tees also also side to side tee marker placement on less busy days (assuming about 15 foot wide minimum)
Also, while the runway look ain't great, it is a fact that the fewer times you pick up the mower blades the quicker you mow, so combining a few tees to longer rectangles would be slightly more effective for mowing. And, thats how Alison did them at Bob O Link......
I sense a growing consensus back to rectangular tees. They certainly are more functional and can be built smaller, and even when placed on rolling ground, sometimes the corners can look kind of cool vs. the round edges generally following the contours.