From testing the Ultimaker 3 seems to have problems with high poly stl files. Such files result in g-code files created by cura with lots of really small moves.  A lot a small moves mean that the main computer needs to send many command to the motion controller in a short time. If the motion controller has run out of commands the print head will stop until it gets a new command. Such small stop can relate to print artifacts.  A possible solution would be to implement the G2/G3 for arch