Thanks for the interesting question. I assume you are adding vertices to divide the facade into the different materials IDs? If that's the case, you could add a wall element to the Corner input, perhaps using a Conditional node to detect the corner angle and switch geometry based on whether it's a real corner or a division on a straight section.
I hope that makes sense. If you'd like further assistance, please feel free to send your scene to firstname.lastname@example.org so we can help further.