I suppose one could envisage such a senate actually reducing sectarianism, by making senators representatives of their sects rather than parliamentarians, thus making parliament (where laws are made) more secular.
Article 3 and 4 stipulates that FPM wants to get rid of the political sectarianism by removing it from Parliament and from the electoral process.
Article 5 says FPM would like to apply the Constitution (Taef) for the creation of a Senate which would represent the religious communities of Lebanon!