Whether the profile declared a readiness beacon at all.
Whether the declared beacon currently matches (page declares itself ready).
Whether any busy marker is currently present-and-visible.
Elapsed settle time so far, ms.
Minimum settle time before we may declare ready, ms.
Whether the last two frames are perceptually similar.
Whether the networkidle fast path resolved (vs. timed out).
Whether a busy marker has been seen busy at any earlier point this settle.
The observable signals for one settle poll.