Tom Doak,
My description of the tee was in terms of the footpad and not the mowing pattern.
With the reliance on riding mowers, rectangular tees are almost extinct, despite the fact that the footpad is rectalinear.
Many tees are constructed above grade for drainange purposes and once a tee is constructed above grade, one should examine the physical nature of the footpad, now the mowing pattern that's evolved over the years.
GCGC's are all rectalinear, including the newest tee, the 12th.
Ditto Seminole, Winged Foot, NGLA and other classic courses.
Many, if not most of the rectilinear tees have rounded corners due to the type of mowers used.
I would think that non-defined tees are more a product of the abilty to drain surface water, whereas constructed, defined tees, were typically elevated and crowned and in a rectalinear form for drainage and alignment purposes.
I wonder if the courses you designed, starting with your first, to your most recent, have evolving tee designs.