Well this one's got a one-way ticket to limboland, but i'll mention it anyway.
Increasing wall masters step speed also increases the distance before they turn inward. Not really a bug, but in the pic I set it at 70, so at that increase changing step to around 180, 190 would cause them to walk the entire width of the screen. There's no documentation for the wall masters so i'm not sure if there's already a misc for this, or was in the works before the feature halt.