Use this style when you want to tie wide areas together. Probably most useful for water areas like rivers, but will be useful whenever you want to create polygons "open" in some areas and "closed" in others.

Any segments next to each other where the azimuth difference is below a tolerance value (you can change the default 45 degree value in the geometry generator), will be highlighted with a line.

Because speed is prioritized there will be some overlapping segments. This is visible when using less opaque lines.