My code is compartmentalized over many files, so I hope I can describe this easily. I have a CGMutablePath() that goes from point A to point B I place an SKSpriteNode at point A and execute:
yourline0 = SKShapeNode()
pathToDraw0.move(to: cgPoints[0])
pathToDraw0.addQuadCurve(to: cgPoints[1], control: cgPoints[2])
yourline0.lineWidth = 0
yourline0.path = pathToDraw0
yourline0.strokeColor = .clear
iconPath0 = pathToDraw0
SKAction.follow(iconPath0, asOffset: false, orientToPath: false, duration: 1))
I execute that SKACtion and as I expected, my SKNode goes from point A to point B. Fine.
I'm not sure how to reverse it, I assumed from the dox that calling that same SKAction as is, would make the SKNode go from point B to A.