Tommy, there are a lot of the newer systems that literally advance and retract the wire in conjunction with the pulse frequency. When someone else is welding and you watch the wire spool on the feeder you can see this happening. I understand that this is how these systems are able to produce almost zero spatter and very precise bead profiles. I believe that Fronius, Miller, and Thermal Arc act in this way. I am not sure whether the Lincoln STT systems do this or if ESAB is up to speed yet.
Now we just need our high-speed welding camera system to capture this in a manner so that you can actually see it happening in the weld puddle. Have a great day and best regards, Allan