Using avios each flight segment is counted, so all stopovers are 'free' in that it costs the same to do one or not.
Forgive me on the semantics.
If I book on one PNR JFK-LHR stopover LHR-FCO
-or-
Two one-way tickets JFK-LHR then LHR-FCO
It's the same thing, so "free" in this case is defined as you're not charging me any extra to do this, but at the same time, you're not actually giving me anything of additional value?
So it looks like the best use of avios is domestic U.S. on AA metal to zones where I would otherwise pay more miles with AAdvantage, or Club Europe hopping. I was going to use them for TATL on AA metal, but don't see the point in that now.
Thanks for the info.