Anybody has a good explanation for _this_ use of grob-transformer?

[David Kastrup]

\relative c' {
  \voiceOne
  \temporary \override TupletNumber.Y-offset =
  #(grob-transformer 'Y-offset (lambda (grob default) default))
  \tuplet 3/2 4 {
    c8 d e f g a b c d e f g
    c,,8^> d e f^> g a b^> c d e^> f g }
}

The result is that all the beams are smashed up in the left border and
the tuplet numbers appear over the respective first notes.  All of which
seems like a seriously messed up X offset rather than the Y offset that
should not even have been changed.

-- 
David Kastrup