Two potential solutions are as follows:

1. Create a shape with no border that matches your background color. Place the shape over the cards that you’re trying to hide. Lock the shape in place.
2. Create a frame around the cards that you’d like to hide. Hide the frame by selecting it and clicking the eyeball-like icon.

While the idea of overlaying with a shape and hiding it is good to remove "clutter", it is not enough when we want to "collapse" it (and not have large portions of "blank" space in the canvas. I think an option to collapse a swimlane is useful, not only in Kanban boards but in product maps as well.

I would love this same feature on User Story Mapping

I would use this too in customer journey mapping. We include screenshots off to the side, linked, but people want to see the screens in the process map/customer journey… but in order to have a good sized resolution, it takes up too much space and is hard to follow. it would be nice to expand/collapse as needed

Yes this would be super helpeful to be able to expand and collapse swimlanes. We need them for journey mapping and would like to be able to just have high level info shown as the base point, and then be able to expand more details like pain points, touchpoints etc.