p.s. To be honest I am still having trouble nailing down how Unlisted is supposed to work. It isn't documented fully.

Unlisted is public but not visible in Federated or Local or Search.

BUT... what about Home?

I assumed it would never show up in Home unless it was boosted, but I've seen unboosted Unlisted replies to conversations I wasn't taking part in.

If someone can point to proper full documentation for Unlisted including its behaviour in Home timelines, that would be fantastic.