On the http route settings page in Notehub, _health_host.qo is listed as a system notefile.
I don’t recall seeing that before. I checked the docs but didn’t see it mentioned.
Taking an (allegedly!) educated guess, I imagine that queue is used for hub.log requests to separate them from Notecard’s own health logs? Kind of makes sense, given the distinction between platform and paid events.
You’re exactly right - _health_host.qo is used for hub.log requests to separate user-generated events from platform-generated events (we just haven’t updated the docs yet!).