We are talking about restoring chat history in-app from one phone to another phone. The Signal app allows you to transfer its state (which you correctly note i

We are talking about restoring chat history in-app from one phone to another phone. The Signal app allows you to transfer its state (which you correctly note is not stored in backups) from Signal running on one phone to Signal running on a second phone on the same LAN. The serialization (I guess) is different on iOS and Android so it only works between phones running the same OS. A lost or broken phone does indeed render the chat history toast, however.