I and some of my friends play rubber bridge at home. Sometimes Chicago. Yes, I did learn at the kitchen table with my grandparents when I was a child. And we played 1M-3M as GF. But that was over four decades ago.
There are other uses for 4!C. Ours is pick a major. South African Texas is interesting, though, because it leaves 4!h and 4!s idle. Maybe for minor-suit slam tries.
I looked at Larry Cohen’s webpage, and was surprised that he is suggesting new minor checkback instead of 2-way. The latter is clearly superior and is one of the earliest conventions I would add.