WPMUdev site Update Notifications Page

Re: the https://premium.wpmudev.org site "Your Update Notifications" page.
Had not seen this before but became aware when we started receiving the following notice: "You have reached your maximum enabled sites for automatic updates. You may change which sites are enabled or upgrade to a higher membership level here » "
I must have missed this in the fine print when signing up as I do not remember this limitation. However - on visiting the Update Notifications page it has every site we ever installed WPMU plugins on - including local development, staging servers and production servers. This means that the same site may be represented on this list 3 times as well as clients that we may no longer manage.
How do we clean up this list to show only active clients with websites in a production environment?