@gwennelsonuk @psyhackological Naturally, Libreboot does provide a lot of patching on top of the various upstreams that it supports. For example, the GRUB payload in Libreboot contains native drivers for xHCI controllers and NVMe SSDs, whereas the upstream GNU GRUB project is missing these.
Coreboot is heavily patched. In some cases, entire boards are supported in Libreboot, where they are not yet merged upstream - nowadays, some boards even appear in Libreboot first, or are stable there first.