Fermata default padding too tight?

[Garrett Fitzgerald]

I just used a \fermata marking on a top-line f2., and it struck me as
much too tight - the dot by the half note almost ran into the bottom
of the fermata. When coming up with an example, I noticed that this
happened for all the notes sitting on ledger lines.

\version "2.16.2"

\relative c'' {
  \time 3/4
%  \override Script #'padding = #1

  c2.\fermata d\fermata e\fermata f\fermata
  g\fermata a\fermata b\fermata c\fermata
}

Adding a bit of padding makes it look better, so I'm wondering if the
default needs to be tweaked for the general case, or if that's too
much.