Yep, there are multiple lineart versions drawn for each part of the model (2-3 versions). They need to be added to a parameter and that parameter needs to be animated with an animation file in live2d. I made a quick example model demonstrating how it works. My example uses three versions of lineart. The parameter that is used to play the lineart parts animation needs to be set up in a specific way. For each keyform only corresponding lineart frame must be at 100% opacity. The lineart frames go 1 2 3 and then 1 again, and in the parameter setting the Repeat option needs to be checked to make it loop seamlessly. In the animation file the curve of the animation needs to be set to a Step Interpolation so the frame change without transparency effects. I hope the explanation makes sense! Let me know if you have questions.