Allow different sounds for each voice

I re-enter songs for male Voice choir (TTBB) and then produce practice CDs for those men who don't read music.
The music I enter is on 2 staves, Tenors on Top stave and Basses on the bottom. That's fine, the music is excellently laid out (automatically by MuseScore), clear and legible.
The issue arises in creating the practice CDs, currently all voices on the stave have the same sound so it's difficult to pick out voice.
What I do, is create another version with 4 staves and copy each voice to a separate stave. I can then give each stave a different sound, emphasising one voice and it works very well.
It's a bit time consuming doing the copy/paste for the Tenors and removing one voice, then repeating for the basses.
It gets worse when the music has repeats, first/second endings and often CD al Coda because all these functions are NOT transferred in the copy/paste.

If each of the 4 voice on a stave could be given its own sound (like the mixer) then my task, I think, becomes trivial.

Is this a possibility?

Another improvement in this area would be to replace the dials & sliders in the Mixer and Play panel with boxes into which I could type values. I have virtually no fine control in my hands, so moving dials and sliders is VERY time consuming and inaccurate. Whereas I can type digits reasonably well so for example, to be able to select a sound in the Mixer and set the Vol to 75 to get 3/4 volume takes no time at all but to move the dial to 3/4 takes me ages and I can't guarantee that it is set at 3/4.

Hope this makes sense to you very helpful technical gurus.