Slow = more heat per millimetre delivered. Two fixes:
1. Lower wire temperature on slow profiles. Some controllers can drive the wire PSU off the spindle PWM — set it to follow feedrate.
2. Speed up the slow side. Most melty faces come from morph cuts where one tower travels much shorter than the other. The tool already warns when the L/R circumference ratio exceeds 1.5× — that's the message about "melting risk on the smaller side." Either rotate the U/V profile (ROTATE UV in the OBJECT bar) to balance, or scale that profile up so it has more perimeter.
1. Lower wire temperature on slow profiles. Some controllers can drive the wire PSU off the spindle PWM — set it to follow feedrate.
2. Speed up the slow side. Most melty faces come from morph cuts where one tower travels much shorter than the other. The tool already warns when the L/R circumference ratio exceeds 1.5× — that's the message about "melting risk on the smaller side." Either rotate the U/V profile (ROTATE UV in the OBJECT bar) to balance, or scale that profile up so it has more perimeter.