However, those other companies that advertise neutered ME are shipping newer Intel platforms where actual x86 hardware initialization is handled by binary blobs

However, those other companies that advertise neutered ME are shipping newer Intel platforms where actual x86 hardware initialization is handled by binary blobs (e.g. Intel FSP). Sandybridge and Ivybridge platforms (e.g. X220/X230) in coreboot are all free software for the x86 part, and that's the majority of it. It's only the ME that isn't. With me_cleaner used, it's very close to Libreboot. X230 used to be worse in coreboot; for instance, it previously had non-free raminit. Nowadays, it's all GPL code.