Something that might be mildly interesting, is that changing previous chat contents change what gets sent in your history even if you never re-sent that message.
User: Hello
Agent: Hello!
edit the first chat (but do not send it)
User: Beep
Agent: Hello!
Now send this message
User: Beep
Agent: Hello!
User: What did I say in the first message?
Agent: You said "Beep"!
