IFMU,
Yes, he does mention the change that Sikorsky would make to the hinge angle of the rudder on a future ABC.
I would quote it, however, when reading the last sentence in the chapter my eye's watered up and the book had to be put down.
"The synchropter may be an idea whose time has come and gone. On the other hand, it may have been ahead of its time and just the right configuration for some future helicopter requirement." 
Dave