Is there a minimum time between prompts for SKStoreReviewController.requestReview()?
The advice our team was given from Apple was to call requestReview after the user completes a “high value” task. For example, in our video app, we call it after the user has completed watching two videos. Doing this, the user is naturally likely to be more satisfied with the app, and more willing to rate it as they are not being interrupted in the middle of a task.
I would recommend putting more effort on identifying the best times to prompt for a review, and let Apple’s code regulate the frequency of the prompts. The exact behavior is likely to be fine-tuned by Apple over time.
It's not documented and there is no (non-hacky) way to detect if the prompt was displayed, hence no way to collect data on this behaviour. Very frustrating!
Personally I throttle the frequency of calls to requestReview to ensure that they are sufficiently spaced out in time and that the first call won't happen before the user has had plenty of time to use the app.