eSun pla+ printed from a k1 max has, in my experience, printed best with a hotend temperature of 215c, a bed temperature of 60c, a print speed of around 50-60mm/s, right in line with the manufacturer recommended specs. If you plan to print eSun pla+ from your k1 max please ensure you follow their recommendations or you may experience print quality issues. Below is an example of eSun pla+ printed at manufacturer recommended temperatures but at a staggering 300mm/a print speed. As you can see, the underextrusion is significant. If you plan to print at high speeds ensure you use a filament designed for it.