Hello, also just found out about this feature request.
I myself wouldn’t necessarily call this a logarithmic volume slider, as it’s the human ears that work in a logarithmic way, so in the slider, you most likely need the opposite, which is a power function.
As already mentioned, this is an issue, mainly because the step at the beginning of the slider is way bigger than the step at the end of the slider (in reality, they are not, they just sound to us like they are). The problem is beautifully explained in https://www.dr-lex.be/info-stuff/volumecontrols.html and https://ux.stackexchange.com/questions/79672/why-dont-commercial-products-use-logarithmic-volume-controls or just see the graph at https://techsupport.cambridgeaudio.com/hc/en-us/articles/360000105437-Amplifiers-Linear-Logarithmic-Volume-Control
After a little bit of tinkering I found it’s actually very easy to implement, all is happening in the dzPlayer.control.setVolume function, which does some things and more interestingly also sets the volume. Sadly, it just uses the linear function (audio player volume = volume), which should be replaced by power of something (audio player volume = Math.pow(volume, ratio)). While messing around, I found out the best value is around ratio of 4. This way the volume controller is behaving in a more “natural” way. If you have no idea what I’m speaking about, no worries, devs will probably know 
