Just a point of clarification:

A12s are confirmed, providing ‘E’ inventory is available when you make the booking. When I worked at HDQ, A12 was how we travled for work, and even if they were paying oversales, you were not off loaded. The trick is picking flights that say ‘book’ vs ‘list’ in the NRTP (sometimes e space does become available after you lost, and it will automatically confirm you 2-7 days before departure). Once you ‘book’, even if you are not immediately assigned a seat, take your PNR to AA.com, and then choose a seat. At that point check in as normal at ~24 hours and it is essentially confirmed. Now not all flights will have ‘E space’ as it is inventory controlled, but at 7 days out, many of hub-to-hub flights still should. I know that this is still not perfect as our schedules are more dynamic than an HDQ employee, but still a good start!