Altdefault breves in chords

[Edward Neeman]

Hello,

The alt-default breves are shifted oddly in chords with seconds and unisons, as 
in the example below:

\version “2.19.80"

{ 
  \time 2/1
   \override NoteHead.style = #'altdefault
   <e' f'>\breve
  <e' \tweak extra-offset #'(-0.213 . 0) f'>\breve 
}

Is there a way to match up the vertical lines of these breves (as in the second 
tweaked chord) by default?

Thanks,
Edward

---
Dr. Edward Neeman
www.neemanpianoduo.com