Figured Bass - accidentals too small

[Michael Käppler]

Hi all,
I don't like the tiny accidentals which are created f.e. by <_!> or <_+> 
in figuredBass mode.
I tried tweaking the font size in BassFigure object, however this 
increases the numbers too. Is there a way to get only the accidentals 
bigger?
By the way, I would like to use the symbol for raised sixths, fourths 
etc., which is much more common in baroque scores than number and "+" or 
"#". It lookes like the note has a small tick at it's top. Maybe anyone 
has already extended the font for this reason.

Any advice would be great.

Michael