Membership - 50 Page Limit

I need to block access to over 50 pages, I have set up the Access Levels and taken the Pages Element into the Negative Rules box, however, it only allow me to select the 50 most recent pages.

I have used a Shortcode editor to create my own short codes and while this will black the on page content it does remove the item from the menu as the 'Page Selection' box does.

Is there a means to 'view all pages' when setting up Access levels?

Is there a better way to block access to pages so as users are unaware of their existence? I need to drip 4 new pages to users each day and then remove them from their experience of the site.