I think is talking about AA FD with a 3x, I have found it for C1-C3 and C4-C2 but is not a 100% FD (1x is possible at 100% FD), besides, AFAIR C1-C2 is not possible (or easy to find) with a simple 3x as others routes.

There is something that I could like learn, when you guys talk about a flyable 1x (as a reposition flight), it means that is possible to take advantage of that because is like Cx-Cy?, because the one that I found are always far far away with the exception of one, which I was there 3 times last month, but I didn't know that a 1x from that City could work with AA for my future trips