>> I never saw any music engraver who uses it.
>
> and most of my piano scores of publishing houses do it like this. I
> have examples here by Schott and Henle.
I think this dispute deserves an issue in our tracker. Obviously,
there are two engraving schools, an older one to which Paolo refers
(and what I would consider standard, too), and a newer one referenced
by Joram.
And please add scanned images of piano music to the tracker! I can
imagine that this eventually leads to two piano pedal styles in
LilyPond.
Werner