Duo-Art pianos really do have the stack split point between D# and E,
giving a bass-treble ratio of 39:41 notes on an 80-note stack!

The split position can be determined from the readily-available QRS
recut test roll, because E is played as one of the themed arpeggios,
and has a treble snakebite.  This treble-themed solo E can also be seen
in many rolls, of course.  A good clear example in a common roll is
during the second chord of the slow second part of Chopin's Scherzo Bb
minor, Op. 31, Duo-Art 6118 played by Josef Hofmann - about 2' 30" into
the roll.

A piano with a 40:40 stack split ratio will fail to accent this E, and
therefore won't perform the music correctly.

Julian Dyer