[indigo945]

> Signal insists on using your phone number too, refusing user ids or anything that will make analysis hard.

That is no longer true, you can use user IDs now.

For the other problem, you can enable self-deleting messages in group chats, limiting the damage when a chat does become compromised. Of course, this doesn't stop any persistent threat, such as law enforcement (is that even the right term anymore?) getting access to an unlocked phone.

[notepad0x90]

It doesn't mean much if it isn't the default, even then people who got it prior to that use phone numbers, you can protect yourself maybe, but not other people in the group. But it's good they're doing this now.