Nice video, but portability is not really a property of a federated system, more a hack that often fails.
Discussion
nostr:npub1melv683fw6n2mvhl5h6dhqd8mqfv3wmxnz4qph83ua4dk4006ezsrt5c24 The video is a bit aspirational in that respect, but people are working on it. No reason it can't be made to work.