I don't think it can make the voice better in this way. All the sources of sound depend on how to supply PI power. Linear power supply must be good? Switching power supply must be bad?
I think that on the current power supply system, any change of a capacitor. The performance of sound will be very different.
Sound source is an important part!
Changing the sampling rate of mpd, increasing or decreasing frequency, is not the right way to do it, and will cause instability of the system.
I personally think that users who will choose to use runeaudio are players who have certain requirements for sound. They also pay more attention to the importance of sound source replay. A bad sound source will certainly not sing well! We should not use other ways to make him better on this basis, only make the really good sound source sing incorrect sound.
Power supply and the hardware is very important (for sure), but implementation of software is also very important. Why do people praise 'Roon'? It's not only the user experience but also the sound, likewise LMS (Logitech) which is still a good product soundwise (user interface can be much better).
And look at good audio/hifi manufacturers who use a RPI as part of their hardware (e.g. Bryston and Metrum Acoustics), ok their hardware chain is good but also the software used for distributing the sound.