LP, problem is that Columbus will not insure the inlaws as they are over 74.
You are right in that insurance is bought for piece of mind, but until someone is in the unfortunate position of having to make a “serious” claim, they really do not know exactly how good the cover is in terms of, in your case Euros and in my case pounds “shillings” and pence.
Forum members should be aware that the Amex policy for Platinum (and Centurion) is very different to the policy through Insurance Services.
Finally, as far as I am aware, again the Plat/Cent cover is the first travel policy which is regulated by the UK FSA. Most insurance travel policies give you the right to refer a complaint to the Financial Ombudsman Service, but they are not legally obligated to abide by the rulings.