It is true that UEFI has better security. Also it has faster boot time as I noticed 7 second boot time in the Windows computer that has it, unlike legacy BIOS.

Recently made computers are using UEFI and not the the legacy BIOS which people called BIOS. Or maybe legacy BIOS is still used on low budget computers. But if you have an old computer that make use of legacy BIOS instead and you need a cold wallet, that means you will not use it?

If my old computer is using legacy BIOS, I will still format and reinstall the OS and use it as cold storage wallet hardware for bitcoin and I am certain that nothing will happen as long as it remain as cold wallet.

But I will appreciate your sincere answer if you will use the old computer with legacy BIOS or not.

It is worth knowing that the old BIOS is referred to as legacy BIOS while the new BIOS is referred to as UEFI or EFI. UEFI is still Basic Input Output System (BIOS).