It's an AC certificate, so AC makes the rules. They'd have to pay OS cold hard cash to upgrade you on its flight, as opposed to upgrading you on one of their own flights where the incremental cost is negligible (or zero, if they'd upgrade someone anyhow).

As posted, the AC forum would be the best place for this question since that's where the AC experts hang out. You may find someone here who knows something about AC's program, but it's chancy. I'd click the Alert a Moderator button (black exclamation point in red triangle under your name) and ask that this thread be moved. That's better than cross-posting, which is against FT policy and likely to get at least one of the two threads closed.