Proposal is that you make additional chat buffer, where lines by each
users are simply appended.

When buffers are destroyed or upon last buffer destroyed the chat
buffer should remain.

Chat buffer offers collaboration line beyong editing buffer and users
do need communication in collaboration.

Chat buffer should open by default, and it should be customizable to
turn it off in general, as some people may use video or sound
collaboration, which tools may already have their own text chat as
well.

Jean