(Layout nitpick) Time signature irregularities (mainly 9/4)

[Risto Vääräniemi]

Hi,

I just noticed that the different time signature numbers are aligned
differently. For instance the "4" in 9/4 is placed a lot lower than in
5/4. I've included two images displaying the issue.

How is this placement done and what might lead to these differences?
Do different numbers have different sizes or something else?

-Risto

time-sig_5-4.png
Description: PNG image

time-sig_9-4.png
Description: PNG image