EDAS supports TPC email discussions for a paper. TPC members and
reviewers can click on the 
icon at the bottom of the paper page to add a note
to the paper discussion. The note is then distributed by email. There
is no special configuration option needed to enable these discussions,
but you can determine who receives copies of the discussion messages by
email via the template configuration. The
Conference:Reviews configuration setting TPC
discussion determines whether messages are sent anonymously, i.e.,
without identifying the discussant, or with the name of person making
the comment.
There is no time limit to the discussion phase. The conference needs to be configured to allow access to the discussion to various roles such as track chairs or session chairs, using the "read review discussion" permission in Conference:Configure, Permissions.