Component overlaps in preview pane

In Burmese I’m using a lot of flipped components where the path direction gets changed, and when these overlap with paths in the normal direction, Glyphs is mostly smart enough to render things without white overlaps. However the preview pane is showing unexpected white overlaps on instances that match master weights (but not on interpolated instances). It would be good to get the preview panel behaving the same as the text window in this regard and fill in all overlaps.