How do BIOS updates work for non-Valve devices running SteamOS?

I haven't found much discussion around this topic, so if anyone has links to existing articles or posts I'd appreciate it! Are there any concerns with the BIOS getting out-of-date if running SteamOS on a device that comes with Windows installed by default? A Lenovo support page, for example, specifies that the version is for devices running Windows. If you want to update the BIOS, do you have to reinstall Windows first?

Any info here would be a big help.