I think Seonon probably evolved into Senuzgda rather than Suno, judging by it's location. Also Vlandian npcs in Pravend mention Sunor sausage or something so I presume Sunor was supposed to be nearby at some point in development. Shame they didn't include the city. In my ck2 playthrough of Legend of Zendar which I then further modified, Suno was the first capital of Calradia, then Praven (Baravenos) when I became a merchant republic and then when I further expanded I moved yet again but Suno is where it all began. Sad not to see it in the end. Aesthetics of placeholder late antiquity imperial cities currently present in the game would have suited it.