The mainboards work stand-alone. There are free STLs to print a case for it or you can buy a case from them.

Basically replacing the mainboard gives you another small PC to use as a desktop/living room/server device. You obviously still need RAM and storage though.

I own a framework 13 and I replaced the mainboard once (due to an issue, they replaced it) and it took less than 10 minutes to swap. It’s expensive for what it is, but in support of their vision I was willing to pay premium for it.

They also argue that they need these high prices due to low volumes with the goal of bringing prices down to be more competitive eventually.

I don’t see why this use-case needs a special distribution?

I have Arch installed alongside Ventoy on a thumb drive with all firmware packages on luks encrypted partitions. I keep it in sync with my other computers in terms of dotfiles, configs, packages so I can boot my usual environment on any PC.

As long as all references to partitions are UUIDs (fstab) or by-uuid block device paths it just works and I don’t see why you couldn’t do that with any other Linux distribution.

It’s right on the page you linked? You have to pay for it.

Free tier says it’s cloudflare branded and only recommended for small hobby projects.