Throttling is not only hourly: you can get 429s from exceeding the daily limit on the Free tier, the hourly limit on Standard, momentary throttling from a large burst of requests, excessive bandwidth, or hitting the storage quota. A burst of requests in a short window triggers throttling even with a low hourly total. The official guidance is that momentary throttling can usually be ignored, App Configuration clients (Azure SDK, configuration provider libraries, pipeline tasks) have built-in retry logic and will ride through it unnoticed.
Source: https://github.com/Azure/AppConfiguration/issues/736
Source: https://github.com/Azure/AppConfiguration/issues/736