in the pcbnew, i noticed the margin layer, when i check the help file, it only tell me this is for a setback outline. i also check some demo file in the kicad fold, but i found they also don’t use the margin layer, only use the edge. Cuts layer. so what purpose this layer is for?
Edge. Cuts
This layer is reserved for the drawing of circuit board outline. Any element (graphic, texts…) placed on this layer appears on all the other layers. Use this layer only to draw board outlines.