for check under USB install , before launching Calamarès
test -d /sys/firmware/efi & & echo UEFI || echo BIOS–> check 2 options on USB boot returns UEFI , but calamarès did not see any other /boot/efi disk , and not on disk install selected ( no partitions , only GPT table )
it not offers option flag Boot & ESP --> bug calamares for OMLX4
( calamarès should check test -d /sys/firmware/efi & & echo UEFI || echo BIOS ,
if UEFI only GPT + grub-EFI , if UEFI[Legacy] * , IF BIOS , MBR only *
with flags ( if mixed is not good also , report errors should be useful )