I tell a lie: the specific computer that I mention in the above post has a cleaned-up version of coreboot on it, not libreboot.

I had a much smaller chromebook with libreboot on in a few years ago. Booting was fine, the rest of the hardware was too weak for my daily use. It was an Asus C201. I vaguely remember having to disconnect the battery and bridge some board contacts to get it switched over.