I think that the Temperature ist not the problem, else the nose would have warped down. But I agree that the fan position are not optimal due to the asymmetrical arrangement. Maybe there is a printable upgrade to optimize air flow like the ones on the UM1.
I also think that it has to do with cura, especially with the gcode flavor: UltiGcode.
I printed the head on a UM1 with gcode flavor: RepRap (Marlin/Sprinter) and I worked much better as u can see
There is still a dot of filament but i could easily remove it with a knife.
Also in the preview of cura the amount added at the end was less but still visible. I have tried these 3, you can see the differences:
I dont know if unchecking the horrible fix a/b changes something but in the preview there is no difference. I have to try a print.
In the past I encounter this problem with the UM1 but this was because the nozel didnt got out of the way at the end of the print fas enough. Wich I could altered in the end gcode. Problem is with the UltiGcode that you cant see or write the code. It only is visible when you select RepRap marlin.
Therefore this must be to 99% a sofware/code problem.
I own a UM1, UM2 and a Replicator 2. I also had few moths ago the new makerbot replicator fifth gen wich i send back because it was a piece of shit.
In comparison I must say that Makerware is much better in handling Prints. I almost never got a fail print. With the UM / cura its always a guess work why things dont print out as planned. But the print quality is by far the best I have seen. Especially with 0.060 layer height. It´s like a resin printer.
Well I will keep trying to solve the problem, I appreciate any suggestion If you get a solution for this problem.