Thank you for your analyses. However I have been an Amex customer for years. And before moving to a Platinum Charge I had the Krisflyer Amex.
Always paid of my credit cards every month. Maybe nothing to earn for them; but at least they could be honest about it.
It
The Krisflyer Amex is a Westpac issued credit card so your credit card history is not visible to Amex.