Vulnerability Checker Extension is part of our security process and the MainWP dashboard has no way to notify users of websites with potential vulnerabilities. Yes we get emails when a vulnerability is detected but the dashboard itself should have a widget or even better yet use the Security Widget to post any outstanding vulnerabilities.
If I miss the email the only way to check is click on the side menu and actually go to the Extensions page (since the Vulnerability Extension is not even listed in the menu) and then click on the extension itself.
Maybe another option for notifications is to add badges with numbers on the menu items that shows items that need to be addressed. So it a vulnerability is detected the Parent menu Item Extensions would have a badge with a 1 in it and then when I opened the extensions menu the child Vulnerability Extension menu item would be visible with a badge with a 1 on it as well.
These badges and how they work could also be used for other important notifications like Plugin Updates, etc…