Can you tell me more about this? Cross device sync without an account is not intuitive to me. I'm about to download it to try it out, but I think it might be useful to update the docs to help people understand how that might work!
The sync is built on top of iroh (https://docs.iroh.computer/what-is-iroh#how-iroh-works).
There is also docs here outlining what Set is doing on top of iroh: https://github.com/rootstring/set/blob/main/docs/sync.md
But yes, I should explain more (or least link to this doc) on the welcome pages. I intend to write a blog post soon as well about how the sync works.
For the current version, the UX is inconvenient, you have to manually paste the pairing code between the devices. I'll add at least discovery soon, where you can automatically discover devices.