Centring vertical staff names

Is it possible to have the S and the A centred instead of right-aligned? I tried changing this in the Edit Names window but it didn’t change the staff name in the score.
staff name.png

You have to adjust the Paragraph Style, I think.

My beef is with the vertical alignment. When using two lines, it always seems a bit high.

Trouble with editing the Paragraph Style is that it then centres all the names. I only want the S/A centred.
The vertical spacing with two lines probably has to do with the vertical padding of the font. I’ve found that if I, in the Edit Instrument Names window I set the Baseline Shift to -2.5 points, the positioning of the staff name is correct, at least for Minion Pro.