I don’'t happen to see them implemented, should I craft a custom xmpp document to do so?
Are you referring to the “Blocking Communication” defined in the XMPP spec? http://www.xmpp.org/specs/rfc3921.html#privacy
Smack does not support that feature yet but it’'s in our roadmap. Smack 2.0 will be full xmpp compliant and this feature is required to do that.