Since all of the actual sequencing will still be taking place on the M3, the Genos will be acting solely as a (live) playback device.
Manual for the Genos:
MIDI configuration starts on page 142
It looks like you may need to load and then modify one of the MIDI templates.
Assuming you connect the M3 MIDI OUT to the Genos MIDI A, you may need to set "Clock" to "MIDI A" (not sure on this one, but seems logical).
Same with Local Control. This may need to be set to OFF (but it may work with it set to ON as well?)
System Exclusive Receive should be ON.
Under the Receive section, assign parts as required, 1-16 if you are connecting with a MIDI cable.
Under External Controller, erm, there's a lot there. Without having the device in front of me, I can only guess that you want to set up a 1 to 1 CC mapping from one to the other.
The receive section has a monitor so you can test out whether your various channels are passing through properly.
Try starting there, let us know how it goes. There are others here with much more MIDI hardware experience that can hopefully help fine tune the settings once the basics are up and running.