Thanks for your detailed explanation. I understand, too much to do, too less time. I appreciate highly what you and your team members do for us. Keep up the good work!
In the mean time I’ve played a round a bit with a setup for a pure-Qt5 replacement for bluedevil-wizard. I can’t promise anything, its a heck of a lot of work for a one-man-pony-show. And…considering that bluedevil-wizard does the job 
I learned already a lot about BlueZ, and the work of the original authors (of bluedevil-wizard). I’ll keep you posted when I have some serious results to mention. This may take a while though, or indefinite.
I found out that Qt has a QtBluetooth-API, which makes interfacing directly via the presumably lower-level BlueZ-interface superfluous. Perhaps mimicking the functionality of bluedevil-wizard will be more straightforward and less cumbersome when using it.