You’ve never used function keys? The dual function is annoying even inside the OS. I have to help several people with laptops and you can’t tell what mode they’re in, the user often doesn’t know either.
On laptops, you never know if the F-key behavior is defined by the OS, BIOS or keyboard driver. I just mash F2, F8, Fn+F2, Fn+F8, Del as often as I can (these are the most common keys to do the trick). You can reduce the options with a USB keyboard with just normal F-keys.
Some laptops don’t have a key you can hold to enter BIOS settings or boot menu (maybe to start booting before the keyboard is initialized?) and there is a reset button hole for that.