I'm new here, so I may be off on this, but your situation goes to 1 of my issues:
Is there a way to transfer from AMEX MR to AA?
It's now not a big deal for me b/c I have already transferred almost all of my points elsewhere, but my AMEX MR is linked to my SPG account, which, in turn, I have linked to my AA account.
Am I missing something or can I (and you) transfer 1:1 from AMEX MR to SPG, then transfer again a little later (at a littler better than 1:1 with bonus for 20k miles transfer) from SPG to AA -- effectively transferring from AMEX MR to AA?