Stan: I believe that was a theoretical concern with the soft lead cube shot available in the 70s - 80s. Orvis promoted a Woodcock load and the box was marked "Not for covey shooting".
I have not heard the issue mentioned with the various plastic insert spreader loads. My limited experience was with Polywad (disc and post) Spreaders in a tightly choked 16g Smith. The pattern was a bit wider and I don't recall fliers, but they could have been off the 36X36 paper.