Chef Server HA - 3 Node Config

I am working on building a new HA Chef Server environment using the new chef-backend packages. I do not want to use more than 3 hosts for both backend and frontend as there is plenty of capacity and redundancy in the my 3 node setup.

I have managed to get the frontend and backend working together by making the following mods to the frontend configuration (/etc/opscode/chef-server.rb)

haproxy[‘local_postgresql_port’] = 15432
haproxy[‘local_elasticsearch_port’] = 19200
postgresql[‘port’] = 15432
opscode_solr4[‘external_url’] = ‘

I was hoping that someone from the Chef HA team could answer two questions:

(1) Is this a “sane” thing to do.
(2) Are there any additional configurations mods that need to be made to /etc/opscode/chef-server.rb to get the frontend and backend living on the same host.

All and any help is much appreciated.