NONE of your use cases would be impacted by a “default value of 2”. This value is STILL changeable via the settings menu, as it would only be the default for new images, not for an upgrade.
The point I’m trying to make on ultimately why all of your use cases are not affected is because the use cases for even adding an SD card, to begin with, are for backups, and/or local storage of media files, in which case no one would choose a small enough card capacity that would make keeping a 2nd backup file problematic. That’s what all of this boils down to. Even your digital signage example, where the number of media files would be limited, if someone IS going to store media, they’re not going to use a low capacity SD-CARD, and if they use the SD-CARD strictly for backups, then keeping a second backup, would not impact even the smallest of cards!
But, responding specifically to your new use cases: 1, 3, and 4 I respond with the same questions: Would they even turn on automatic backups? if they did, would their SD card be overtaxed with an additional backup?
Case 2: If they have turned on automatic backups and set that to 30, this doesn’t even affect them. It would only be the default value for newly installed images. I’m not saying “force the value to 2” I’m saying, “modify the existing default of 1 to 2” for the build of install images.
And while every single user might not benefit from a default value of 2, enough would, to make it a viable change request, especially when compared to the “cost” of storage of a second backup to all the use cases you’ve suggested.
Your system deleted my older backup file (which held all my custom addons, their default settings and data, etc), because I installed a new image, turned on “backup on upgrade”, without changing the current default value of 1, and then did an immediate upgrade. Fortunately I was able to rebuild the a lot of what was lost (though I did have to repopulate data and the settings, etc.)
Using your “granny” extreme, let’s say the son had changed the setting to keep 3 backups, but granny started poking around in the settings, then just slides the bar down to 1 or 2, and clicks ok. Without any prompt, the “extra” backups are basically marked for automatic delete on the next update.
If you wanted to avoid any and all possible conflicts, then this change request could be to add logic such that any modification of the setting for “backup on update”, or if the value for number of backups to keep is changed, run a check if there are existing files over the value specified, then do a prompt to confirm marking the “extra” files for deletion. That’s just a whole lot of work for something that could easily be fixed by keeping two files as the default.
I just don’t understand why you’re even fighting me on this. Is this personal for you? Are you the one that decided 1 would be the default, and you don’t want to change because of that? Help me understand. I’m on the spectrum, so if there is some kind of non-rational process at play here, then I’m not seeing it.