This won't work at my company - all air ticket purchases must be done via Amex Corporate Travel using the company ghost card. I can't even book online and have Amex ticket it with an agent because the contract forbids disclosing the ghost card number to a travel vendor.

On top of this, Amex travel is unable (well, unwilling) to accept more than one CC for payment. I've tried getting them to price out the lowest available coach ticket, then the lowest available FC ticket and charge the coach cost to the ghost card and the difference to my card - but they refused (too complicated for them ).

I think this rule would benefit alot of customers, not just myself - so I'd like CO to consider it. Since you're restricted to the same exact flights, it can't be used to get around the change-flights-pay-a-fee rule, and thus has no real downside for the airline, at least nothing I can see.