Nice looks like I have another upgrade to try.
Qidi Tech just sold me a complete dual extruder assy. with cooling fan for a great price ($55) to replace the one my older model had without the cooling fan. I soldered a connector in the blank fan space on the board and it works fine with full software control. I'm still on the creator firmware. The only real difference between new and older MK10 extruders is the one with the cooling fan has tapped holes in the end of the cool block to attach the cooling fan mount. All these parts are available separately on ebay.