TethysGame::AddMessage has two forms, one of which takes a unit to centre on, the other which takes coordinates in pixel format.
I only used the unit form. So, it would, in theory have to centre on a unit every time. Yet, it goes to (1,512) every time. There is not much I can do about this.
The right-hand side settings (Morale Steady, Day/Night, Disasters, starting units) are disabled, because they don't really have a use. I could easily enable Day/Night (though it would still be static), if demand is high.