I use devuan personally and would recommend, very happy with it
- "Management Engine (ME), also known as the Intel Manageability Engine, is an autonomous subsystem that has been incorporated in virtually all of Intel's processor chipsets since 2008" ... so libreboot supports only older Intel platforms like Napa, Montevina, Eagle Lake, Lakeport (2004-2006)
- "Libreboot has support for AMD hardware of Family 15h (Bulldozer or Piledriver, ~2012 gen)"
This means AMD is the best shot for say libreboot, but there are some other problems with hardware security i believe, ethernet port being one IIRC, this is eliminated by using USB ethernet adapter.
More reading https://libreboot.org/faq.html