ZZ Flyer,
I had similar results with the polywad, depending on the load and the yardage... so the rule is true, pattern any load especially when you are experimenting with spreders.
When the polywad works withou a hole in the center, it does give a much more open effect than the X spreaders. Full choke to about IC, the X only gives about Full to mod.
I agree with Jim about the BP spreaders, they are a pain and I haven't used up all that I bought. I instead went to the X spreader that is from BP and inserted into the shot cup before crimping.
I have tried a few not shotcup wads from BP, but haven't patterned them yet.
Jerry