I definitely agree that places to look for inspirations for expansions
to the line would include Buchla and Serge. Those who haven't done so
really owe it to themselves to check out:

www.buchla.com and

http://www.scampers.com/EGRES/

As for a DCO, though ... hmm. I just don't see it at all. There are so
many other sources for that -- unless I'm missing a subtlety here.