The seedsigner hardware with the SeedHammer OS needs to know your seed, cause it works as controller for the engraving machine. The machine only has a psi and a cnc stepper driver installed.. But as the ss hardware is airgapped and has no means of communication via Bluetooth or wlan, I don’t see a problem with that. Also before entering or scanning a seed the Ui demands you to extract the sd card with the Software on it - wich i think is neat.