Regarding the question of disabling the chat during Retreats and Builds Phases, there is no point in trying to "match the boardgame" that does not allow to discuss during Retreats nor Builds Phase.
Indeed, when you play the boardgame, you are physically at the same place and at the same time than all the other players. As a consequece, players have all the time they need for their negotiations.
On the contrary, this is an online play. Not everybody has 24 hours internet. Not everybody has "everywhere internet". And so, if the Phase is 24 hours, for example, we sometimes need the extra negotiation time during the Retreats or Builds Phase, especially with players all around the world that live in all those different time zones.
If it was prohibited here to negotiate during the Retreats and the Builds Phase, the consequence would naturally be that players would create games with longer Phases !
Finally, the idea of disabling chat during Retreats and Builds Phases only for the players who have orders is terribly unfair because then, during those Phases, only the other players would have the possibility to negotiate their actions for the next turn !