Hi. I am seeing the mentioned warnings ( WARNING: Unknown key type EIGHT_LEVEL_LEVEL_FIVE_LOCK ) whenever setupcon is executed on a stable buster installation.
The contents of my /etc/default/keyboard is as follows: ---<snip>--- XKBMODEL="sun_type7_euro_usb" XKBLAYOUT="de,de" XKBVARIANT=",neo" XKBOPTIONS="grp:rwin_toggle,ctrl:nocaps" BACKSPACE="guess" ---<snip>--- These warnings appear since I enabled the "neo" variant.