The Volume Level setting does not seem to affect the volume very much until it is set to low levels. It may be due to the logarithmic nature of (perceived?) volume levels not being taken into account. I know shamefully little about how that works.
I had the Volume Level set to 15/100 and after a track ended, the volume was quite loud on the following track. I had to adjust the Volume Level setting to make it kick into effect again. This is not reproducible 100% of the time, so more data will be needed.