I too hope this thread will prove informative.
I think BA Silver (OW Sapphire) deals the benefits the OP is looking for from this side of the Pond.
In the AA program I get the impression Exec Plat >> Plat, but I've not really looked in to that aspect as qualifying is beyond my travel pattern (I would always need BA Silver as a min before branching out).
HOWEVER ... gaining AA miles is very much something I'd seriously look at (and using my BA Silver), as the burn side is often better for point to point trips.
8 Intl upgrades for Exec Plat ... Hmmm, wonder if that means a (in early planning) DONEx credited to AA rather than BA would be a thing for me to fret over?