Sadly, I lack expertise on that bluetooth integration thing

And now for something completely different (and not Spanish Inquisition, too) i I would like to finally determine if your's device current draw is normal or not (which, in extension, will tell us if it's worthwhile to dig that nightmare'ish bluetooth integration topic deeper).

Could you, please, download the attachment (of this post) file to MyDocs, then, execute as root:

...and perform two following tests:

1. Disable cellular, wifi, and all other connections, close all programs etc (just like for powertop test), and execute (as root):

Ignore error after modprobe -r, if bq27x00_battery is not found, and after executing bq27200.sh 20, lock the screen and leave device idle for ~5 minutes. Then, unlock it, stop the process (ctrl+x), and post output here.

2. Do the same test as with #1, but this time, with cellular (although no data connection) and your other usual "standby" things enabled (screen still locked). Also post output here.

Cheers,
/Estel