I often use “Assign Background” to make a comparison between the current and another (second) font to check the position of composed glyphs or accents or whatever.
But if there are components in the glyph to be assigned I will have components of the current font in the background. So it would be nice to get a decomposed path from the orginal (second) font in the background.
Sure. But of course it is not the same font every time.
And more important, the result of the feature in this case is not, what I would expect. It makes not really sense, to have a copy of the positions of composites of another font, when I call “Assign Background”. Don’t you think?