"The only grip I have with BB is it should allow for the drum tracks to be split out to separate audio files..
kick.wav snare.wav etc..."

In the BiaB file structure there are audio files of each drum RD and at the end of the audio file there are examples of each sound used by the RD drummer. You can use these to double the RD track or you can volume shape the sound out of the RD track and have only the selected sound, e.g., snare on it's own track for whatever effects you choose. I often double the snare.

Back to the song. Dunno if you use mastering software but with Ozone it is very easy to, e.g., add clean bottom end to the production w/o revisiting the mix...unless the mix is bad which yours is clearly not...at all.

Pardon the ramble we REALLY enjoyed the spin!

J&B