Then C will be added to A's sortfeeds list and the processing order will be retained: [A, B, C].
My question is: when does A actually get C's output data? If JACK allows the connection, then A should get as input C's output data. Is there a one-cycle delay? That's kind of what I interpreted this to mean.
I also read this but didn't walk away with a clear idea of what JACK actually does.