So... why is it so important to declare it if it will not be covered either way?
It gives you the opportunity to pay a higher premium and get it covered or look for other companies willing to cover.
The most disturbing thing I have heard was an example of an insurance company weaseling when they have no right to. Apparently a holiday in Europe with a NZ motorbike licence, they fell off and injured themselves. Put in claim and the insurance company denied because they did not have an international driving permit - which is in affect a document that is written in multiple languages to accompany your licence, there is no testing etc.
This Weasel behaviour is rubbish, and takes advantage of people who are ignorant.