There are some sites that don't properly invoke Chrome's triggering logic to prompt users to enable Flash Player.

Having a way (site settings) to enable Flash Player for those sites (ideally persistently) would provide a viable workaround to users.

One of the historic concerns has been that users could add a *.* exception, which would effectively act like Allow Always.  [Strawman] To avoid this case, perhaps we could make it so that users could only add a site exceptions, in an enterprise locked down mode, from the Site Settings UI.  We could make it so that users could delete custom entries but not add them by hand.