Has anyone done this upgrade?
It looks quite useful, however, I question the heatsink not being completely mounted to the extruder.
I'm guessing the heatsink doesn't do much since it's not mounted tightly. My guess: it's used to prevent the air from blowing directly into the extruder and not necessarily for cooling.
The door hinge upgrade looks useful, but, as I stated, the heatsink basically rests against the extruder. If it's meant to draw heat away from the extruder, it seems this will cause less thermal conduction.