I've wanted to deal with Digitakts "Midi Loopback" for quite some time, but I just got around to it today and what can I say - I'm pretty excited about the possibilities it opens up. In a nutshell: you plug the Midi Out into the Midi in and get 8 additional LFOs which can modulate ALL CC parameters of the Digitakt, not only the usual LFO destinations.
In this track I'm using the loopback for creating an evolving granular background texture that's based on a simple piano sample. Multiple LFOs constantly vary reverb volume, reverb frequency, the loop position and bitreduction at the same time, resulting in a constantly changing sound. Fascinating.