Yes, that's precisely why I like the CBA card - as you add in the pre-existing conditions on the form and update, you see the additional costs involved.
Last time I filled the form out, I put in that my wife and I had both had back operations, which added a whopping nearly extra $800 to it, which I unhappily paid.
Then I thought about it, rang Allianz up and said to the lady that I was concerned about the payment I'd made a few days ago - why am I paying so much money for something our surgeon now says the problem is fixed - especially as we each have rods and screws in there, making us more re-inforced than normal people?
The lady said that it was simple. She would cancel the policy for me and refund the money, and I could then go and redo the form leaving out the back operations, but that if anything should happen to our backs, we wouldn't be covered. Which is what I did.
I'm always annoyed by those forms whch ask whether a Doctor has ever recommended I take Cholesterol pills. The answer is Yes. But there is no space to write that multiple Doctors subsequently told me not to take the pills, and that my cholesterol levels are now fine. So the answer remains a Yes, but it's one of the strikes against you which adds to the cost of premiums for pre-existing conditions.
At the end of the day, you don't need the CBA card, but might find it wise that one of the cards you have uses Allianz for its travel insurance.
Cheers,
Renato