For what it's worth, here are also [1] the Framework community forum thread about Arch and [2] the Arch wiki page about Framework in case you're interested.
I'm still waiting for mine to arrive (in the next batch) but I plan to install Manjaro when it does, and am cautiously optimistic that it'll be mostly painless.
Might be worth noting, I forgot about this when making my original comment, I wasn't able to get my USB drive for it to boot without disabling secure boot, but secure boot isn't something I care about so it wasn't a problem for me. I've heard it works but I can't comment on the specifics of it.