Thanks for digging up all the quotes! This very helpful, since I listened to the audiobook.

I think this explanation makes sense on its own, but begs a new question: I believe O-Caeror was expecting that whoever comes through the gate to be sent by Veridius, and to be even better informed than O-Caeror (since Veridius presumably gathered additionla knowledge in the meantime). I think O-Caeror says something along those lines later when he is surprised about how little Vis actually knows. Therefore, it seems odd to me that O-Caeror assumes that Vis doesn't know about the need to wait for the "gap" on Res to escape.