1. The minimum length before retraction . Used to avoid frequent retraction. No need to
change.
2. Enable Combing: Digital for surface quality , the nozzle will try not to go through surface ,
that’s why Cura is better than Slic3r.
3. Minimum extrusion length , to avoid frequent extrusion.
4. The height extruder rise in the retraction . If you need to set this option , 2mm is suitable .