sorry to be a downer, but this is nonsense. what you have noticed with the dots is pure coincidence. whether the dots stand still or move forward or back or are a blur depends on the platter speed compaired to the quartz clock (which is at 60hz, i believe, inherited from the ac switch).

they have nothing to do with the tempo of the record on that deck, and certainly have nothing to do with the tempo of the record on the other deck. touching the platter will cause the dots to jump around, but it means nothing to the mix.