I guess ymmv, but I was never able to under volt my phone past -50 on CC... And even then I would crash once a week. That's the breaks.
Oh and strangely enough, I had this crash issue using navigation a while back... I ended up fixing it by forcing all navigation calls through Maps or Yelp or something. Now Maps has a lab that does navigation bubbles that is exactly what I needed.
~Tapatalk'd from my Fascinate