I'll try disabling within the next days and let you know.
The main result from trying all the distros is always the same - it does not work. However, sometimes I can't even connect to the speaker, sometime it crashes, sometimes there is just no sound.
I know that the Raspi Zero (W) is not designed to be a media system but I assume the HW works. What keeps me going is the fact that bluetooth audio is working with Raspbian Jessie and VLC but yet not using any other software I've tried so far...That's why I still think this is some kind of software problem and may be fixed in the future.