Hi nusenu,
Since you posted to tor-dev I guess you're asking for community input too. About your use cases, Onionoo is for obtaining data about running relays, not tor network health, or BWAuth activity. You can answer this question by looking at the latest consensus data from CollecTor, counting relays, and unmeasured. So this use case is out of the scope of Onionoo use. Your second use case doesn't help the operator debug.
What does not being measured mean in the context posed by the ticket? (whichever, boolean or int)
a) the relay was not measured b) the relay was supposed to be measured but didn't respond c) the relay was supposed to be measured but the measurement was blocked due to network interference d) the relay was measured but the threshold number of measurements was not obtained ... and so on. Not being measured doesn't help with debugging. The only thing which matters is being `measured` in which case a relay has consensus weight.
The only data which can be relied upon, and which is also a property of a running relay that has been measured is consensus weight. You can track this using the Weights document.
I hope that helps --leeroy