The fact of the matter is that there should be very little sound difference in your sample rate converted and dithered file when compared to the full fidelity file. Properly done the 16 bit file should play like it has the detail of a 19-20 bit source.
To do this depends on having a good sample rate converter and a good dither generator. Always sample rate convert first and then dither with triangular noise shaping.
Yes, you may hear it differently at 16 bit, but it should still be VERY good if your master was very good.
Not all daws process the music without changing it.