Excitation (audio signal) in USB host mode

I am afraid Axoloti cannot sync with the digital audio input or become a slave of this signal. It can only get analog audio.

My question then changes to how to create embedded audio synths for Tickle. USB MIDI is not a problem usually, but the audio part it is. We will need at least a raspi or similar computer. It would be great with Axoloti or OWL or similar… any plan?