I just release version 0.3.0 of this plugin. The following changes have been implemented:
Using action:analytics.increment for analytics counter (better performance and accuracy)
Added label viewer to page view that can have the values user, guest, or bot (inspired by an upcoming change in 1.11, you get it early here)
Added new metric nodebb_online_guests
Added new metric nodebb_eventloop_lag_seconds. This is measured by NodeBB which has a smoothing factored compared to what is measured by NodeJS and provided via nodejs_eventloop_lag_seconds
Added new metric nodebb_eventloop_maxlag_seconds. This is the maximum allowed lag for NodeBB. If the lag is getting closer to this value NodeBB will start to issue 503 error codes. The chance a user is getting a 503 is calculate by this formula: (lag - maxLage) / maxLag.
Sorry it took a while but your metric for online guests is now finally available.