I'm aware of that. I used to run an xmpp server and recently switched to Telegram for inter-family conversations (wife, brother, intimate friends) because the xmpp UX story is unfortunately not perfect (you need message carbons, you need stream management and you probably want MAM to have a usable system that can be used on mobiles as well).
This is great news! Such a big fan of the work you guys are doing at Whisper Systems. We are in the middle of an update to Umbrella App (which contains lessons on digital and physical), so will add the latest Signal changes to it in the next few days.