Thank you for sharing details.
Understood that we can't directly access drive in iOS.
Could you please tell us what will be the best way to provide seamless transition to our app when flash drive connected to give better user experience ?
e.g. Import Photo's from drive via Photo's app, this provides pop up similar like "Would you like to delete the imported photo from attached camera?" with "Delete" and "keep" button.
We would like to check below things here
1) Once import complete it should automatically transit to our app [Without pressing on Home key and manually transiting to our app]
Please suggest better way to transit to our app.
2) Customize this popup to have "Delete All" functionality. [As you mentioned, it looks impossible]
Not possible for your app to inject itself into nor affect the Photos/card connect/asset import process for any purpose.
Your users must manually navigate to/select photo and video assets managed by the Photos app*, post import.
If this is a feature you'd like to see going forward, feel free to submit an enhancement request via the bug reporter, linked below, adding your report # to your thread for reference, thanks and good luck.