Tim Yup, those advanced settings caused some understandable but unexpected rejections for me as well, so I can understand this decision.
However, an optional country whitelist for online transactions to me seems like a rather easy to understand security mechanism. I do know that Amazon transactions usually come from Luxembourg which might be unexpected for some users either, but I'd still think this would be a great addition to the security settings for advanced users.
Will check out the topic you suggested.