Discussion
How do you access your coins then?
Depends on the device.
Foundation Passport and Seed Signer use QR codes to sign transactions.
Coldcard Q uses QR codes (not sure about SD card option) and the MK4 uses a micro SD card to sign transactions.
Foundation has the Envoy companion app, though best to use Sparrow Wallet for all of them, an excellent desktop app where you can view your balance and create/manage transactions.