There are ancient messages on the forums about how imported curves are recognized as polygons: empty stroke, non-empty fill. However, that’s not the complete list of requirements. Imported SVG curves must also be polylines. SVG Bezier curves, even with empty stroke and non-empty fill, are only imported as linear features.
Issue #1: I work over the imported curves in the source application, so I want to preserve Bezier handles during import. The source application is much more convenient than WM to use for curve tweaking, matching curves to sketched original images, etc.
Issue #2: You can weld the first and last vertexes of a linear layout shape, but you can’t convert a linear shape to a polygon shape.
Issue #3: Once a polyline has been imported, if you turn on Use Bezier Curves and perform curve smoothing, there is a glitch at the welded first/last curves, which must be manually straightened out by pulling Bezier handles.
At the moment, I can import smooth, tweaked Bezier curves, but only as linear features, not areas. I must import polylines to get areas, then re-do Bezier handle tweaking in Layout Generator. The process is painful on a large extent and/or a large curve, and the results are not as good as the original smoothed curves, due to the clumsiness of the UI and the lack of the original reference sketches to match.
Feature request #1: Ability to import SVG Bezier curves as areas (polygons) with Use Bezier Curves already applied.
Feature request #2: Ability to convert a layout shape between linear and polygon shapes. A precondition that all vertexes are welded would be fine.