I have a small mono synth that makes good bass sounds (Korg Monologue), and it also has poly midi which I use sometimes via usb.
So, my question is:
Could I have my Digitakt sequencing my monologue while also using the monologue keyboard to play the DN?
Yes this should be possible.
DT Midi out → Monologue Midi in (use the same midi channel)
Monologue Midi out → DN Midi in (use the same midi channel)
On the Monologue you need to set “Local SW” to off. This way you disconnect the keyboard from the audio circuitry and still send midi messages.