Re: But
Thanks for the tip!
From other online comments*, GalliumOS may be getting less maintenance done presently, but it's a place to start. Wikipedia indicates that a Chromebook can be tricky to "unlock" - you may need to replace the firmware - and the GalliumOS community has expertise for that. And if that gets you to another Linux distro afterwards - that sounds all right.
* https://linustechtips.com/topic/1375478-thoughts-on-galliumos/