I'd recommend including instructions in the email on how they can verify the SD card is loaded with the correct data. (e.g., `dd | sha256sum == curl | sha256sum

I'd recommend including instructions in the email on how they can verify the SD card is loaded with the correct data. (e.g., `dd | sha256sum == curl | sha256sum`). This, I think would give you the best of both worlds. (Those are shell pipes (`|`) in my example.)