Glyph "flags-stem" Missing

[Fairchild]

Recently upgraded from LilyPond 2.0.1 to 2.4.3, Windows XP.  The glyph
"flags-stem" now seems to be missing from the Feta font set.  Don't need it
for the stem, but it has been the only way discovered to insert a vertical
line.  Can fake it with slur control points, but the resulting line has
variable width.

Is there a way to control the slur line to constant thickness?

If not, a rather general and useful feature might be to provide a
uniform-thickness user settable property for the slur interface.

Thanks.