https://www.sarducd.it/index.php
SARDU MultiBoot Creator: UEFI or Bios Legacy Mode bootable USB Flash Drive builder. All In One for computer maintenance
sardumultibootcreatorbioslegacy
https://www.0xf8.org/2020/03/recreating-isos-that-boot-from-both-dvd-and-mass-storage-such-as-usb-sticks-and-in-both-legacy-bios-and-uefi-environments/
mass storageisosbootdvd
https://linuxiac.com/fedora-plans-to-drop-support-for-legacy-bios-systems/
Apr 7, 2022 - The Fedora 37 development team is considering dropping support for non-UEFI BIOS.
legacy biosfedoraplansdropsupport