Meridian put ferrites on the cables connecting the ID40 card to the network (was it one on each end?) on the Anniversary 808.X. They developed this further into the ID41 where the isolation was achieved in the card (no more ferrites).

Meridian haven't missed this trick.

Personally I would have thought 8 seconds would be enough to hear a difference unless it was quite subtle. Bias is a little difficult to avoid.