Right, I think I’ve found a workaround if anyone was interested.
Download THIS PLUGIN and install it.
Then in your new page categories section, add a category ‘noshare’ or anything else that won’t affect your other categories, and select this new category for all pages that you wanted to omit.
In the Nextscripts ‘settings’ tab, scroll down to the Categories filter and drop ‘noshare’ in, and EXCLUDE.
In the Nextscripts ‘reposter’ tab, scroll down to the categories filter and do the same as above.
When I saved the new settings in my reposters, there were three pages missing, which I assume were those that I chose to omit.
Obviously this will be of no use to those Nextscripts users that are already INcluding categories as there is only one option to either include, or exclude, all categories – so we’ll leave Nextscripts to explore ways of getting a more permanent workaround that will let you either include or exclude individual pages.