collision-detecting engraver?

[Kieren MacMillan]

Hello all!
…and in particular David N., who I think will find this a fascinating puzzle  :)

In the Piano/Conductor scores for my musicals, I like to include the chord 
symbols for those who can use them. A survey of representative scores shows 
that, while there is no defined standard as to placement, a significant portion 
(~40%) place them where I prefer, i.e., between the two piano staves. (The 
other popular spot is above the vocal staff, which is where they sit for nearly 
100% of commercial “vocal selections” and “piano/guitar” songbooks.)

The problem, of course, is that dynamics sit in the same slot [between the 
piano staves]. Therefore, there can be a lot of collisions. Lilypond does a 
pretty remarkable job of vertical spacing when there are no horizontal 
collisions. (Kudos to everyone involved in making that true!). However, when 
there are collisions, they require [a lot of] manual tweaking, of three types:

1. Move the chord symbol slightly to the right of the “proper moment”. This 
works especially for single, simple, absolute dynamic marks.
2. Skip the chord symbol entirely for that moment. This works when the chord is 
obvious or repeated or whatever.
3. Juggle both dynamic(s) and chord symbol(s) along both axes. This happens 
when both are necessary, and the dynamic is “long” (e.g., a hairpin, or “f, 
molto marcatissimo”, etc.)

I would love Lilypond to automatically do #1 or #2 unless told otherwise.
(Well, actually, since #3 would be done manually anyway, Lilypond would be 
expected to do #1 or #2 only, I suppose…)

Is such a thing possible?
If so, how much work would it take to make happen?

Thanks!
Kieren.

p.s. Here’s a minimal test case:

\version "2.19"

theNotes = {
  \repeat unfold 3 { R1 }
}

theChords = \chordmode {
  g1 g1:7 c1
}

theDynamics = {
  s1 s\mf s
}

\score {
  \new PianoStaff <<
    \new Staff \theNotes
    \new ChordNames \theChords
    \new Dynamics \theDynamics
    \new Staff \theNotes
  >>
}