x86_64 - Console quirks: Linux
Once you have booted into netboot.xyz on x86_64, if you plan on using Linux images, you must still set up custom Kernel cmdline params under Utilities (UEFI).

Set Kernel cmdline params: [] to console=ttyS0,9600.

If you make a mistake, move with arrow keys, and use the Delete key.

Once you have typed it in, you might have to press the Escape key twice.