Which is the default OPNSense image used by Nitrokey Gmbh to setup NW678

Hi all,
I feel lucky I ordered 1 NW678 unit last year bet. Can someone from Nitrokey staff advise which is the image used to setup the NW678. I would like to reinstall latest fresh version and need to know which is the typical image used. I saw from the menu that com port is setup for GPS/PPS setup. Need confirmation which one is used

  • vga

  • dvd

From the forums I saw I need to plug in usb keyboard, press esc+number of the drive i would like to boot from.
I’d appreciate feedback to know which is the better image to use and reinstall.