With a 30" Cinema display my dock icons even at the largest setting are rather small. I could never find the VOX icon and had to keep using mission control to bring it up. I then realized the problem - rather than a constant icon which I would immediately see and recognize the icon changes with the album cover. That's a really cool feature, but in my case it means I have to go searching through all of the icons in the dock to figure out which one is vox.
Pinning it to the dock in a specific location after Tidal sort of works. But I always hesitate since the icon changes wondering if I really want to bring this up since I don't recognize the album cover since it is so small.
Your vox icon is one of the most recognizable ones (and best) ones that I have on my dock ....