Has anyone checked out SPLEETER?  I started using it recently for making all my own backing tracks to play with (in Go Play Along).  But it would work great for CDLC too!

https://research.deezer.com/projects/spleeter.html

You can extract out all the tracks, then using audacity, create a backing track with just DRUMS and VOCALS.   It was hit or miss until version 1.54, but now its solid and does an amazing job with the tracks.  They released a video on how to do it here a while back, but it still works the same:

 

I found a gui version for people who can't handle python, it it quite large and takes a while to install tho.

It's fun to screw around with and it's results on a few songs really blew my expectations, others didn't work well at all but that's just how it goes sometimes.

Might be useful for tabbing bass on certain songs if you can handle the waiting time and it gives you a decent output.