Thanks Garfield and CMB for the very kind comments. Much appreciated.
@Garfield - Yes, this was most definitely not "generative" (which implies a mostly set-it-and-forget-it type of thing). It was a very hands-on "performance" of the patch. I was constantly making changes and I'm actually amazed I managed not to hit one wrong note on the Keystep. ;-)
That specific part you called out at 16:14 was one of the sections with just the M32 and the Starlab, and the resonance was being modulated by Sloths which just happened to peak along with the Cutoff, which was being modulated by Maths which was patched to itself to be pretty unpredictable. A nice happy accident.
I am loving the Iridium. It's great out of the box, but it's also very easy to do sound designing - especially for dynamic ambient sounds. The Mod Matrix is the best I have seen. Once you spend a few hours with the UI you'll love it.
Cheers!