User rated ★★★(ok feet)
Including your latest find, Rihanna wears size 41 heels in every photo where it is shown (posted far below in the wall).
However EU 41 doesn't equal USW 11. According to the standards, the "range" of EU 41 overlaps with USW 9.5-10.
The page you linked is incorrect for at least one good reason. Try this one instead:
By the way, there is no such thing as Italian size or French size: European manufacturers use the ancient "French point" which is proportional to the foot length in centimetres: EU = 3/2 L(cm)
This is also the reason why the relation USW = EU - 30 is FALSE. It is practically true for smaller sizes, 5 through 7.
Sorry for the boring/OCD post.