I am not sure why sketchup does not like faces with too many sides. Modifications on such a face takes forever. A single face with 65K edges is on the too much side. You can always add redundant softened planar edges to divide the whole face to faces with each one having manageable number of faces.
💡 LightUp 7.1 | SketchUp's only real-time renderer that uses object-based rendering
Download Trial
K