FWIW the top FD pictured with the large vertical expanse of the back plate was developed for the 52/39/30 triples. If used on
52/42/30 triples it would catch on the 42 when upshifting to the 52, but clears the 39t ok. The earliest triple FDs in the
modern era were closer to the short vertical expanse of the second RD pictured.