I don't disagree that one might perceive a small physical slop with a 1/8" chain on a 3/32" cog or freewheel if the chainline isn't dead on. Might come back to you in the way of weird vibration passed to you by drivetrain feedback, felt through the pedals. While likely a very, very small thing, I don't think Xgecko is crazy or imagining things.