The original part designed by Prusa (as shown above) includes a cone for precise placement of this part within the overall extruder assembly. However, this part ("Adapter-Printer") does not require the cone for precise placement as the other extruder parts surround this part and ensure exact placement.
It is desirable to have this "Adapter-Printer" easily removable because its location in the filament feed path is subject to accumulation of dust and lint, which can negatively affect performance of the filament sensor. My redesign makes the part easily removable; only one screw has to be removed from the extruder assembly to expose this part and make it accessible for removal.