> get ZFS on a USB drive but all of that is done at your own risk.
I don't consider ZFS on portable devices to be more risky than FAT32. You can always copy the files to two devices instead of one. Or carry around multiple SD cards.
> though you can apply a readonly policy to RAW images.
Snapshots will protect you if files are corrupted after they make their way to the file system.
> Bad SD card reader and bad RAM or bugs in any of the 3 machines are still a risk.
Sure they are. But they are not in your control (except RAM, where you can always pay for ECC). I would worry about things that are.
I don't consider ZFS on portable devices to be more risky than FAT32. You can always copy the files to two devices instead of one. Or carry around multiple SD cards.
> though you can apply a readonly policy to RAW images.
Snapshots will protect you if files are corrupted after they make their way to the file system.
> Bad SD card reader and bad RAM or bugs in any of the 3 machines are still a risk.
Sure they are. But they are not in your control (except RAM, where you can always pay for ECC). I would worry about things that are.