Sounds like not a bad idea for the tool, but very niche.
Theoretically, something similar can be achieved with a read-only partition, or a read-only installation (e.g. Fedora Silverblue). I won’t argue that may include more competency than just throwing some ISOs at the partition. But for me, that feels like a more comfortable way of having a rescue system at hand. I have an Arch installation USB for the same reasons, to save my Arch installation if anything happens. I had been thinking of creating a separate USB with Arch installed, but I’m not sure it’s needed. As in reality all of my maintenances were to boot, chroot and update or downgrade some things. In case I need a GUI, I use a Fedora installation. I assume your scenario is more like that.
Theoretically, something similar can be achieved with a read-only partition, or a read-only installation (e.g. Fedora Silverblue). I won’t argue that may include more competency than just throwing some ISOs at the partition. But for me, that feels like a more comfortable way of having a rescue system at hand. I have an Arch installation USB for the same reasons, to save my Arch installation if anything happens. I had been thinking of creating a separate USB with Arch installed, but I’m not sure it’s needed. As in reality all of my maintenances were to boot, chroot and update or downgrade some things. In case I need a GUI, I use a Fedora installation. I assume your scenario is more like that.