Now, after several hours of continuous PLA printing (approx 7h @ 27 °C / 81° F ambient) with my PP3DP Up Plus 2 3D printer and a lot of PLA failures due to clogging (by PLA overheating) in the past (with software v2.11 and v2.12), I am now able to print (3rd-party) PLA flawless on the printer (have not tried the PP3DP PLA yet).
After a pretty decent clogging with a boiling extruder stepper motor (due to heavy overload), a slightly damaged extruder gear and melted plastic parts I decided to design a cooler for the stepper motor. It works surprisingly well cooling the extruder motor as well as removing enough heat to enable serious PLA printing with this machine.
The outer cover is reverse engineered from the original one (big thanks to you PP3DP for providing the parts with your Software, hopefully you don't mind my little "copy and paste" :-)) it is equipped with holes for a 40 mm fan. To avoid any unnecessary flow losses and too much cooling air on the part I made an additional inner duct. PLEASE: DO NOT GULE them together!!
I don't know if it is possible to hook it onto the same circuit parallel with the existing fan. A quick look at the main board showed no obvious fan controller so probably it is all hooked up to one beefy 12V voltage regulator.
The other mods you can see on the pictures: http://www.thingiverse.com/thing:253694 and on some http://www.thingiverse.com/thing:253687 (You don't want to use thing:253687 with PLA!)
UPDATE: Added a bunch of stuff, first of all http://www.thingiverse.com/thing:413198, secondly heat sinks and a more powerful fan 7000 rpm (13,6 m^3/h or 8 CFM), for details check the pictures!
Print the duct without any support ("Only Base" option in print settings), The cover requires a support but only for a small part of the cover.