While experimenting, I found out that the endpoints of splines can extend so that they stay together until they split off. Unfortunately, however, I do not understand how this works. I managed to do this by duplicating, subdividing and warping the spline, but I did not extrude it. As soon as you extrude, the ends don't stay together.
Here you can see what I mean: Even though the splits are much longer, the ends do not rush ahead when extruded, but stay level with the respective shorter spline.
My goal is to apply this to lightning bolts that are created via a script. Unfortunately, as you can see here, the endpoints of the splines don't stay with each other at all until they split off, but they split off at some point afterwards.
Is there any way I can control the speed at which the splines extend? Is there perhaps a trick with the geometry nodes?