Dynamically update CollisionPolygon2D at runtime?

I have a stacked area chart like the supplied image (but often slightly more complex).

Each polygon doesn't have all too many points and renders efficiently.

This chart often updates with a tween that takes ~2 seconds, changing the Polygon2Ds.

But I want to be able to highlight a specific polygon by hovering it, so I added a CollisionPolygon2D to each Polygon2D. So when updating a Polygon2D I also do:

collision.polygon = polygon.polygon

This operation works but takes several hundred milliseconds to perform so I definitely can't run it every tween loop or every frame. My best bet, I think, is to run it in the middle of the tween (since I use ease-ease). But even this lags the UI for a good half a second when the update is performed.

I think this is due to the CollisionPolygon2D needing to be rebuilt everytime a new polygon is assigned which takes a crazy long time even for simple shapes.

Any suggestions what I can do differently?

The best course of action was to skip using a CollisionPolygon2D at all and instead just check Geometry2D.is_point_in_polygon(pos, polygon.polygon) on the visual Polygon2D. Where pos is the position of the mouse.