Instead of re-downloading the entire region, implement a versioning strategy. Store the OfflineRegionDefinition with a customId (e.g., "region_version_2"). Use offlineManager->listRegions() to compare metadata and delete old regions before creating new ones.
There is a tangible speed difference between fetching data over LTE/Wi-Fi and fetching it from local storage. While vector rendering is CPU-intensive, the data retrieval becomes instant with offline packs, leading to snappier map loads. mbgl-offline