Backups rarely get tested and when they get tested they sometimes fail.
So I propose a solution: A program is configured to write its files through a driver*. The driver decides where to save and open files from.
Every time the application is shut down, the file system driver makes a backup and then when the software is re- opened it switches to a backup location and reads and writes from there.
This way your backup media gets tested.
*FUSE or Windows Or Windows File system proxy https://github.com/billziss- gh/winfsp-- chronological, Mar 02 2020random, halfbakery