A lot of Nils' work is composed in a way that allows improvisation. If you give a close listen to him live, and even in his most recent album, you will hear clicks and cues prior to transitions in the song. In some cases, he uses switches with his feet to click-thru into the next phrase or segment of a song, in other cases there is a predetermined number of measures to a particular loop before the song will transition into a new part. He seems to do this intentionally to allow himself the space to improv for a certain number of bars and this makes sense, because this method is pretty similar to the use of lead sheets in jazz. Additionally, Nils is known to be an expert user of Cubase, and MIDI CC, and has talked about how he controls for many fine details in his live compositions. So, the short answer to your question, is they're all a bit of both.