In standalone mode, surround outputs don't seem to be working properly. in ASIO settings, I am only able to enable 1 stereo output and 1 input. The manual does not mention anything specific to enabling multiple audio outputs in the settings section:
https://native-instruments.com/ni-tech-manuals/absynth-6-user-guide/en/installation-and-setup
I've tried holding down alt, ctrl, and shift. How do you associate the specific internal surround output to the hardware output?