Shortcode: exclude category

Hi,

This shortcode shows downloads from members category.
[downloads category=”members”]

We wonder if it is possible to get the opposite case: downloads from any categories but members category.

Otherwise be able to set a default category when a download is created. So we will create a category public and set public as default category.
The add this shortcode [downloads category=”public”]
I’ve seen that there there is a exclude option but it’s only for post ID not for category slugs.

Adding category=”public” seems to be the bes option but user could forget to assign the category, that’s why I suggest to “set default category”.
We want to avoid to use just [downloads] because it would show a list of public and private downloads. And private links should remain hidden.

Many thanks