In theory the data is sat there on the eMMC storage and could/should be readable to make a backup *but* the data is on an EXT4 partition that cannot be read under Windows and I'm not sure 5Ninja's ever released Linux drivers/tools for mounting the storage.
An old IT saying/proverb states there are only two type of computer users: a) those who back-up their data with religious conviction, b) those who haven't lost all their data in a mishap yet" .. which is kind of true.
I shifted my DB stuff into a central MySQL DB some time ago as I'm hopping between different test devices all the time, but that's also another good way to make endpoint devices a bit more stateless.