Tor Browser for Android is screenshottable using the Google Assistant
Given FLAG_SECURE is true, a screenshot cannot be taken by normal means. However if you hold down the home button to activate the inbuilt Google Assistant and click on the 'Share Screenshot' button, a screenshot can be captured successfully.
This totally circumvents the privacy protection of not being able to capture screen while in Tor Browser.
To upload designs, you'll need to enable LFS and have admin enable hashed storage. More information