Accidentals centred above notes

[Richard Shann]

The example given in the docs for placing a sharp on a prall results in
a sharp which seems slightly too far to the left:
http://www.lilypond.org/doc/v2.18/Documentation/notation/expressive-marks-attached-to-notes#articulations-and-ornamentations

\version "2.18.0"

\relative c''' {
  \once \override TextScript.script-priority = #-100
  a2^\prall^\markup { \sharp }

  \once \override Script.script-priority = #-100
  a2^\prall^\markup { \sharp }
}

Is this considered best typesetting practice? Looking further at the
docs I see that the same question could be asked of the examples at
http://www.lilypond.org/doc/v2.18/Documentation/notation/typesetting-mensural-music#index-Musica-ficta

where

fis gis
\set suggestAccidentals = ##t
ais bis

is given as an example for printing accidentals above notes. In this
case too the sharps seem to me just slightly too far to the left.

The bottom line here is: is this something that will be changed in
future versions of LilyPond (in which case any -\tweak #'X-offset #'0.2
added will later prove a liability)?

Richard