Update:
Support answered fast and told me:
The new Halion Sonic 7 works right out of the box!
I tested it: wuhuuu it works 
Halion Sonic SE 3 does not work out of the box.
It does work as I described above under MacOs → you need to set an “Aggregated Device”. This means you combine the internal Mac Mini output with the Motu M4 audiointerface. Well actually it is enough to set the tick just for the Motu M4.
Here a screenshot for all the people who use Halion Sonic SE 3:
- Open the MacOs Tool “Audio-Midi-Setup”
- click the + (down left corner)
- then use this Aggregated Device / Multiausgangsgerät in Halion Sonic SE 3
