Thank you for the comments, karbock.
I will admit that as I was putting it together, my liking for this skin, on a horizontal scale, kept on moving around like one of BoringName's VU meters.
One moment, I'd be happy with the look and the next I'd feel it was too dull. My eyes sure had to do some adjusting but I now prefer it as my main.
since there are no colours to differentiate GUI elements, I would make column headers stand out more by using a different background shade for them.
For example, the headers of the column browser, especially when it's placed vertically. But that's just an idea for future experiments.
That I can look into doing for sure - I've had to brighten some dark elements to compensate for the lack of colour disparity (context to save the day).
You mean headers like 'album' here, right?

the time display for the current track (top or bottom panel) has a variable font size which follows the size of the custom font set in Layout (1) -> top panelh
I will investigate this closely. But it shouldn't be any different to the behaviour in the other two because everything was a basic copy & paste without alterations to this effect.