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.