Hello Dan,
Yes it is true that I do not use the original cube power supply. Because with 24 volt the hot end did heat up very quickly. With 19 volt this goes more smooth. So a matter of (may be stupid) feeling.
Below a video of printing with 0.25 mm layer and print speed 35 mm/s. If I print much faster the extruder is skipping steps.
With regard to printing with non cube filament I have read in this forum that the diameter of the cube filament is about 1.6 mm. I measure 1.7. I did not try yet but I am surprised that with filament of 1.75 people get problems with the extruder. What is your opinion about that.
Frits
https://www.youtube.com/watch?v=rB7T0G71Jms&feature=youtu.be