Why do some sit when making kidusch Schabbes morning in contrast to the Friday evening kidusch, when they stand?

Friday night kiddush is considered "testimony" of God's creation (read the translation), and testimony in a Jewish court must be given standing. On the other hand, sitting during kiddush represents more "Qeviut" [permanence] and shows that we are clearly sitting down for a meal (for there is no kiddush without an immediate meal). Accordingly, Shabbat morning, where there is no aspect of "testimony", we prefer showing "Qeviut", and for that reason, some even sit for kiddush on Friday night (feeling this is more important than the symbolic standing for "testimony"), or sit down after the testimony of that 1st paragraph of Vay'chulu.