polyphonic tuplets + accidentals = spacing mess

[Mark Polesky]

The accidentals in polyphonic tuplets are disrupting the
horizontal spacing here.  In the example file that follows, I
wanted the notes of the second line to be typeset with the spacing
found in the first line.  I tried *everything*, and humorously,
things only got further and further from the desired spacing.  Now
I'm deferring to the wise sages here.

How can this be solved?
- Mark

* * * * * * * * * *

\version "2.13.22"

\paper {
  indent = #0
  ragged-right = ##f
}

\markup "desired spacing:"
\relative d'' {
  <<
    { d4 d d2 }
    \\
    { g,4 \times 4/7 { g16 g g g fis g g } g2 }
  >> |
  b1 | b1 | b1 |
}

music = \relative d'' {
  <<
    { d4 d8 ees d2 }
    \\
    { g,4 \times 4/7 { g16 g g g fis g g } g2 }
  >> |
  b1 | b1 | b1 |
}

\markup "adding an E-flat 8th note disrupts the spacing:"
{ \music }

\markup "with strict-note-spacing:"
{
  \override Score.SpacingSpanner #'strict-note-spacing = ##t
  \music
}

\markup "with uniform-stretching:"
{
  \override Score.SpacingSpanner #'uniform-stretching = ##t
  \music
}

\markup "with strict-note-spacing and uniform-stretching:"
{
  \override Score.SpacingSpanner #'strict-note-spacing = ##t
  \override Score.SpacingSpanner #'uniform-stretching = ##t
  \music
}

\markup "with uniform-stretching and base-shortest-duration=(1/4):"
{
  \override Score.SpacingSpanner #'uniform-stretching = ##t
  \override Score.SpacingSpanner #'base-shortest-duration =
    #(ly:make-moment 1 4)
  \music
}

\markup "with uniform-stretching and \\newSpacingSection's:"
\relative d'' {
  \override Score.SpacingSpanner #'uniform-stretching = ##t
  <<
    { d4
      \newSpacingSection
      d8 ees
      \newSpacingSection
      d2 }
    \\
    { g,4 \times 4/7 { g16 g g g fis g g } g2 }
  >> |
  b1 | b1 | b1 |
}

\markup "with uniform-stretching and proportionalNotationDuration:"
\relative d'' {
  \override Score.SpacingSpanner #'uniform-stretching = ##t
  <<
    { d4
      \set Score.proportionalNotationDuration = #(ly:make-moment 1 8)
      d8 ees
      \unset Score.proportionalNotationDuration
      d2 }
    \\
    { g,4 \times 4/7 { g16 g g g fis g g } g2 }
  >> |
  b1 | b1 | b1 |
}