When working on Italics scaling is always a pain, because there will be some distortion that has to be corrected.
I was wondering if it would be possible to have a trapezoïdic kinda scaling. This would make it possible to scale slanted glyphs horizontally as if you were shoving a trapezoid (slanted rectangle at the italic angle) together. All sides would than stay parallel.
Vertically it could than be along the Italic angle.