Cut Cocoon Form after planarization for even contact area with ground

Hello,

I would like to get an output geometry, which is even for connecting the cocoon with a base, form-fitting. At this point I would manually need to use solid difference and choose the most suitable part to cut the geometry with a extruded rectangle.

Do you know a more elegant solution to this?

Thanks & BR

Cut Cocoon Form after planarization.gh (60.9 KB)