@grindhold@hexmasteen it’s the only one I know of off hand, because PeerTube creates a fake “peertube” user which other AP instances can follow for the full feed. For example, you could even instance follow my PeerTube instance from Mastodon, by following @peertube. Most other AP implementations rely on relays instead of this psuedo-user approach, which both instance operators have to opt in to.