But in addition to these 7 days, I would also like to have 1 monthly version (just one), to have a greater extent of backup history.
This way, older things could be accessed more easily, at the same time without taking up too much space.
DISCLAIMER: It's been over two years since I set up my current collection of FFS batch files, so my recollection may be a little rusty. If my idea is off the mark, that's the reason, and I apologize in advance.
How about just making a copy of your "daily" backup batch job and renaming it with "monthly" in the filename? Then edit the "monthly" batch job to specify different versioning options (a different folder for "monthly" versioned backups and more suitable "last X days," "minimum," and "maximum" options). Then run the "monthly" batch job instead of the daily job on the first day of each month, either manually or as a scheduled task.
If your daily backup batch job is intricate and you frequently edit it, you'll need to decide which is less tedious: duplicating exactly the same edits in the existing monthly backup job, or making a new copy of the edited daily backup job and re-applying the appropriate versioning changes to the new "monthly" copy. (In my experience, it depends on the edits and on the particulars of the batch job in question.)
Note that if you make both the daily and monthly backup folders subfolders of the same parent folder, e.g.:
...\Backups\Daily
...\Backups\Monthly
that would make it trivial to instantly list both types of backups in a single window using a tool like voidtools' Everything in Windows [or fsearch in Linux]. Just run a search on the ...\Backups folder, add the base filename of the file you're interested in to the search box, and sort in reverse chronological order.
Maybe someone else has a better idea, but that's probably how I would go about it.
