Hi @rschirin - thanks for your interest in querying Heartbeat data.
Unfortunately there's no easy way to do this out-of-the-box. Our team has had similar challenges when discussing features like this for the Uptime application. We typically focus on overall number down within a given span, rather than tracking individual ordering of pings. For example, that's how the query responsible for tracking monitor status rules/alerting works.
It might be possible to do this using a custom scripted metric aggregation, but that would not be easy to visualize.