>"Canoeboot is a special fork of Libreboot, maintained in parallel to it by the same developer (Leah Rowe), who maintains both projects. Canoeboot removes all binary blobs from coreboot, thereby providing a fully Free Software coreboot distro, unlike Libreboot which has a more pragmatic Binary Blob Reduction Policy which allows Libreboot to support more hardware. Canoeboot is provided for Free Software purists, who only want Free Software, regardless of technical details. Canoeboot even removes CPU microcode updates, regardless of the negative impact this can have on system stability."
Although being familiar with Coreboot and Libreboot, I never knew about about Canoeboot until I found the web page a few minutes ago...
Looks like it could be worth exploring!