Seedsigner follows a different concept, raspberry pi zero / no secure element / stateless by default
Discussion
I see - no need for secure element if it’s airgapped by design, which also eliminates that same connectivity as an attack vector - do I have that right?
in my opinion it is about the stateless feature. If the device always forgets the seed, you do not need a closed source secure element
airgapped is more about the fact that you don't use a standard data connection like usb