Hi, at least the DJM2000 has the same behavior. I know because I read an article about it and this "feature" has been criticized there :-)
I don't know why the 900NXS2 behavior would be a problem, from my workflow, the first thing I do with the next track to play is proper leveling with all EQs at 12' clock, then cueing, beatmatching and in last step mixing.
If you are doing leveling the same way for each input channel, all channels have same volume. and ya should be fine. Also - as Pulse mentioned - the advantage is then that your cue/master volume on headphone is independent of actual master output.
It would be interesting to know why this is critical for you?
Regards
Markus