So was just looking at the print head and wondering about fitting a Dual BMG extruder and noticed a small issue with the fan cooling duct which is easily solved and will increase the airflow a bit more as the 30mm fan is actually reasonably decent in terms of current draw at (0.1Amp) which has a direct relationship to airflow.
Have a look at the link https://youtu.be/pVamH5ljwdY