You can use other payloads that allow booting from USB, but they are quite outdated, like seabios or if you know how to boot from USB with grub cli then grub payload, however, usually tianocore is used because it is open source and gives usual interface
So libreboot + payload replaces uefi right? Why did you say tianocore is uefi? Whenever i hear uefi i’m thinking about proprietary boot firmware, and thats why I advocated for including libreboot instead of uefi in theese chips. I don’t understand where is uefi in this libreboot + tianocore or whatever payload