My current Midi routing with Keystep, Digitakt, Digitone is the following:
Keystep Midi Out -> Digitakt Midi In
Digitakt Midi Out -> Digitone Midi In
Digitone Midi Thru -> Keystep Midi In
I did this so that I could use the Digitakt as my clock source, which is less jittery and easier to control than the Keystep, but I also needed to send clock to my Keystep so that I could use the Arp in time with the BPM. I have my Midi channels set up so that 9, 10, 11, 12 on the Digitakt correspond with T1, 2, 3, and 4 on my Digitone. I’ve set Auto channel on both to Midi channel 16 so that I can play in something from the Keystep to whatever track I have selected. I do this because using the Auto Channel is the only way to parameter lock note trigs from a Midi controller. (That I know of) I have Track 16 set to Channel 16 on my Digitakt.
My audio routing is:
Digitone Output LR -> Digitakt Output LR
I do this to use the compressor on the Digitakt and I’m really enjoying the new global Input settings. So much nicer than having to copy the settings on Digitone patterns.
This also allows me to throw a couple of other inputs to the Digitone effects, sometimes I will play a long field recording into the Digitone as texture and use the input effects on that.