Making flags a bit thicker? Changing distance between key signature elements?

[Stanislav]

Hello everybody!
I have been developing tactile stave music notation for 
the visually impaired. I am going to make a score with 
subsequent milling on a CNC machine. Now I mainly 
use Musescore, which is a wonderful piece of software, 
but as of yet it cannot change the width of flags 
and chance distance between key signature elements. 
Can those things be done in Lilypond? 
In such case I would prepare the score in 
Musescore and then import it into 
Lilypond and do the rest.
Please help!