We typically recommend using multiple MicroSD cards. But if that is cost prohibitive, you can backup the entire raw disk using Linux’s dd command.
Put the MicroSD card in another computer and use:
sudo dd if=/dev/BLOCK_DEVICE bs=1M status=progress | zstd > IMAGE.img.zst
Replace BLOCK_DEVICE with the device that the MicroSD card.
To restore:
zstdcat IMAGE.img.zst | sudo dd of=/dev/BLOCK_DEVICE bs=1M iflag=fullblock status=progress
You can give it a try to make sure the command works properly. It’s a little slow since it may have to back up the entire MicroSD card including empty space.