Read my post in the ezDrummer topic:
Basically you don’t need to use seperate midi channels because AD can route all instrument to different (audio)channels by itself.
What you need to do is forget about instrument tracks and load AD in the VST instrument rack.
The last icon in the VST instrument rack after the “e” (edit) icon let’s you activate all outputs.
OH and you need to tell AD to send every AD mixer channel to a seperate output this is done by pressing the ”Out” button (has an arrow pointing downwards, located below the solo/mute buttons on every channel of the AD mixer).
AD manual page 14.