I understand that by using the generic CF free cert, https terminates at CF and the connection CF->Origin is over unencrypted HTTP. Is this why there is latency overhead? Because CF cannot connect to origin via https so it cannot open a persistent tunnel? Or is it because the overhead of keeping an open https tunnel per origin server is prohibitively expensive to maintain for every free customer?
I assume that even though there is no persistent tunnel, CF still must still use persistent TCP connections?