@mrniceguy The steps will be correct if the amount of infill the the extruder pushes will be exactly three amount it was commanded to push.
Usually you mark something like 120 or 150mm on the filament measured from the top of the extruder. Then you extrude 100mm at 1mm/s. When this is finished measure the distance between the top of the extruder and your mark. With the result you can adjust your steps.
Your day that at higher speeds it does extruder much less. What do you consider higher speeds? The Anet Hotend will extruder significantly less already at 4 to 6mm/s.