Before FasTrack came out, thete was this runor in Houston about some sort of Super O 2.0. When I saw the available track for the first time, it was O36, and it had the short uncoupling track. First words out of my mpith was "Super O Dash 2!" ("Dash 2" like the EMD line)
I do not know why both Super O and very early FT has the short round electromagnet uncoupling track. Seems FT went to a 5" short uncoupling track. Makes sense. Why didn't SO?