• [ ] Save the working configuration before editing.
• [ ] Record pin assignments for heaters, thermistors, fans, motors, endstops, and probe.
• [ ] Record rotation distance / steps, microsteps, and motor direction.
• [ ] Record bed dimensions, travel limits, and probe offsets.
• [ ] Record thermistor and heater types.
• [ ] Keep a known-good copy separate from experimental changes.

Do not copy a configuration blindly from another printer. Verify board revision, wiring, pinout, thermistor type, heater voltage, and probe model.