De-Legro,
That would defeat the point, one of the things it would reinforce is the idea that while there is war and whatnot going on, decorum is still very important and it's not like the nobles are peasants.
A little thing like a war is no fit excuse for poor manners, while I don't know that Japanese "Winter Court" type events are really theme appropriate, at least on the fairly inbred isles where there is a lot of cross realm conversation, it makes sense.
I guess it'll be covered under dip-immunity, but it would require the permission of the other realm's rulers, which they may not be willing to grant. That however makes some sense, as it's not like nobles could just go and visit who they wanted during a time of war.
