RingStatePollingConfig

how long a ring must go without a participant's ring status changing before polling begins. This is the trade the whole fallback turns on: a shorter quiet period recovers a dropped outcome sooner, and also makes rings whose callee is merely slow to answer pay for a read they did not need. The default is tuned for the first, because a caller stuck on a ringing screen is a visible failure and an extra read is not.

the gap between reads once polling has begun. Measured from the end of one read to the start of the next, so a slow read widens the gap rather than being absorbed by it.