Side point about BIOS – it would be technically not too hard for a BIOS to offer an option to check out all hard drives – see which drives/partitions look like they are setup as EFI bootable & which look like legacy setups, same for USB sticks, same for CD/DVD drives, etc. – offer a menu of choices based on what is found – on a modern PC that might take an extra half a second or something to do and it would be a good ez/safety mode. I’ve never seen that implemented as an option. I see confusion over which USB images are which type of boot & what has to be set in the BIOS options to achieve it. Current practice seems painfully unnecessary.