Backups on a mixer can be done through UC Surface 1.3+ (firmware version 6452 or later) through the Backup tab on the Settings page of the mixer found on your UC Surface application.
Video overview of the Basic Settings of UC Surface (Backup Tab - see 2:17 into the video):
Inversely, there is a way to save individual scenes and presets located on a mixer from UC Surface software. These functions are listed on this below video.
Saving Scenes on UC Surface 1.3+ (see video at 2:06):
Note that device memory can always be found on the "Documents" folder of the computer saving "Local" memory. The file structures found on Mac and PC are as follows:
Mac HD/Users/[Username]/Documents/PreSonus/StudioLive AI/Library/Presets/Scene
***For iOS Users: The application holds all data in it "locally," until the application is deleted from the iPad. You can retrieve this information from iTunes after connecting the device to your computer, and going to the Misc Data area where the scenes and presets are stored.