In other game (Bioware game) for PC that don't have specific name, they will call us by last name (Shepard, Hawk) or title (Commander, Champion).
What about Greedfall? I can imagine that some will call PC De Sardet, some may call Lady, Sir. Constantin just simply call PC cousin. And Native surely have some name from their language to call PC.
PS. I love to hear NPC call me by first name. I will happy if SPIDER give me specific first name name as long as I can customize and role play my character.