Part / Staff naming in MS4

Is there a simple way to understand how parts / instruments / staves are named in MS4?

Here's an example - open a blank Symphony Orchestra score using the template, press "I" to open the instruments panel, and then add "Violin" as a new instrument. This shows up as "Violin" in the score, in Parts, and in the Mixer. If I want to change the name of this to "Solo Violin" for clarity, I need to (1) right click on the staff in the score, select "Staff / Part Properties" and change the name in part properties - this makes the update in the main score. But then, I need to (2) open the Parts interface at the top of the interface screen, find the part named "Violin", click on the three-dot menu, and rename the part to "Solo Violin". This gives me the updated name on the score as well as in separate parts - but (3) still doesn't change the name in the mixer (which still shows "Violin", when I want it to say "Solo Violin").

I guess I have two questions - how do you change the name that appears in the mixer (I still haven't figured that out), and why isn't there one place to change a part name that propagates to all locations?