On Stack Overflow, there are currently 110 flags shown in the toolbar. For those unaware, this is fondly known as the "bat signal", and it allows 10K users to view flags and help moderators determine what to do with the flags that are in the queue.
According to official sources, the bat signal is never displayed if there are less than 5 flags in the queue. On Stack Overflow, I've never seen the queue below about 90, so I pretty much see it all the time.
When I hit 10K, it was an exciting moment. I got what I call the "moderator experience" on Stack Overflow, and I was able to finally help with flags.
Flag Queue on MSO, Facilitated by a Userscript: SO Flags User Script
However, when I hit 10K on Meta Stack Overflow, and when I hit 2K on The Workplace Beta SE, it was a pretty uneventful experience that really didn't compare to Stack Overflow. These sites, like many others on the network, rarely, if ever, get more than a few flags at a time. On Project Management Stack Exchange we actually had 6 flags once, but that was only because the Community bot auto-flagged some posts that the moderators were closing as part of a site cleanup. It wasn't very exciting.
On smaller sites and beta sites, it's important to get the community engaged in site moderation, and showing the flags next to the tools link is one way to announce to high rep users that there are problems that he or she may be able to help with. This is yet another breadcrumb that could potentially be used to lead such users to the flag queue so they may weigh in with an opinion, recommendation, or even take action in conjunction with other users with access to moderation tools.
The Workplace SE Beta Flag Queue, Courtesy of the Userscript:
I understand the need to rate limit requests to the server and to limit computational operations on Stack Overflow since there are just so many people, but on the smaller sites, I can't imagine this is a problem that outweighs the benefits of getting people more involved.
I'd like to see the threshold to display flags reduced from 5 to 1 on beta sites, and we should consider doing the same on sites with lower than an average of 5 simultaneous flags. This results in more eyes on these flags, empowers more experienced users with the knowledge to take action, and also allows these users to also have the "moderator experience".
I picture an option in the diamond moderator tools where the moderators can activate this feature on their site. On some beta sites with lower community participation thresholds, this could be helpful, while on busier sites with many loud users, it could be problematic. I'd prefer to put this in the hands of the moderators on each site.