A few articles I've read mention using a device such as a fat finger to add sustain to an instrument that's prone to dead spots? Would a Hipshot D-tuner, besides having the obvious benefit of an on-the-fly drop D, add enough weight to the neck to have a noticable impact on sustain? Or is the whole fat finger etc. deal a bunch of balderdash? My '78 P is pretty bad around the 7th fret on the G string so I've been investigating this issue.