Not really sure which synth should sequence which but I’m going to assume the following goal:

  1. Arturia key step can play the Digitone, Taiga, Typhon
  2. Digitone can sequence the Taiga or the Typhon via its sequencer (sequence you recorded by playing the keystep)

If so, I guess the following setup should work:

a. keystep OUT into the IN of the Digitone
b. The Digitone OUT into the IN of the CME
c. CME THRU 1 to Taiga, THRU 2 to Typhon

Now, let’s say you want to record a sequence for the Typhon onto the Digitone and play that sequence back from the Digitone:

d. set the Digitone MIDI track1 to send on channel 5 (in the MIDI track 1 settings active channel 5)
e. set the Typhon channel to receive on 5
f. set the keystep channel to 5

If you play your keystep, you should hear your Typhon (you might need to have the MIDI track 1 selected and active for it to work, not sure)
If so, record on the Digitone what you wanna play. If you press Play, the Digitone should play back the sequence to the Typhon.