Hi @chriswmackey, My suggestion is to implement the support for multiple viewports in the viewport filter for LB Preview VisualizationSet as such: ```python for vp in self.viewport: if vp is None \ or vp.lower() == args.Viewport.Name.lower(): ``` instead of https://github.com/ladybug-tools/ladybug-grasshopper/blob/87143434cf8a2a7407eec15b8eee2023db87f2d3/ladybug_grasshopper/src/LB%20Preview%20VisualizationSet.py#L227-L228 and of course setting the viewport_ input to list access in Grasshopper. Kind regards, Marc