I had the following queries for One Drive (they apply to both iOS and Android): 1) I wanted to know how often, and how quickly, photos from 'My Photos' folder will sync with One Drive (if I 'sync on mobile data' is enabled). From experimenting it isn't instantaneous, but usually done within an hour or two, and trying to understand the justificaiton for the time. Does One Drive 'check' every hour for example)?
2) If I delete the copy that has uploaded to my one drive, but not in my photos folder, will it re sync to One Drive next time the App syncs 'checks'?
I contacted Microsoft and they responded (in a surprisingly efficient and informative way which is a nice change for any custoemr servcie team) with the following, which I believe helped answer my Qs:
"When Use Mobile Network option is enabled in the Camera upload settings, photos or videos from the phone's gallery will be uploaded to OneDrive even when your phone is not connected to the Wi-Fi. The time taken to upload the photos to OneDrive can vary depending on the size of the file, number of files being uploaded, speed of the Mobile data received.
When the Camera upload is enabled from OneDrive Settings, OneDrive will continuously check for new photos and videos from your gallery. For example, your photos and videos has completely uploaded to OneDrive, but if you take a fresh picture or record a new video, the same will be uploaded immediately. Please note, this applies only when you have allowed to upload both on Wi-Fi and Mobile Data from the settings.
OneDrive does not upload a photos or videos twice from the same device if the file that has been uploaded to OneDrive is deleted as the same metadata will be recorded in the OneDrive. This is to ensure that your photos or videos are not duplicated. Yet, you will be able to manually select the files from the gallery and upload it to OneDrive.
We hope this answers your question. Please let us know if you have any doubts or questions.