OK, I did the experiments with my phenomenal, “hard to get”, polystyrene and foil Electrocube 410B large caps. They were very good but I still would like to stay with high quality polypropylene caps. The best polypropylene was just less Hi-Fi-ish, less anxious, with reacher and more complex sound. Based upon the RTX, 410B, GE, AC and some other polystyrene I sumized that there is not needs for me to pursue for the large size polystyrene and foil caps.
"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche