Chordname accidental munging

[Shamus]

First of all, I must congratulate the developers on all the nice 
features that have been added to Lilypond since the 1.x days. I've been 
getting much more mileage out of lily since then, and I really 
appreciate all the hard work that you guys have put into it. :-)

My problem lately is that while I've been able to tweak the functional 
(yet ugly) stuff that hangs off of the chord letter to my liking with 
custom definitions, I've yet to discover an easy way to tweak the 
accidental sign that hangs off of the chord letter. I did notice that 
documentation says that you can write a function to override 
chordRootNamer, but my scheme-fu is rather weak and I have no idea how 
I'd go about doing this.

One other thing: Is there a way to do

\set chordNameExceptions = #popChords

globally? It seems that lily only likes that syntax inside of my 
\chordmode definition and I'd like to do it in my external custom chord 
definition file. Right now I have

popChordsMusic =
{
... lots of chord defs snipped here ...
}

popChords = #(append
   (sequential-music-to-chord-exceptions popChordsMusic #t)
      ignatzekExceptions)

in my external chord definition file and I'd like to put that 
chordNameExceptions line in there too so I don't have to tweak every 
\chordmode context, i.e., it should be like the english.ly file--you 
include it and you're done. Is this even possible?

-- Shamus