Hello Matthias,
Yes its more or less like I suspected. The Shape -> Subdivide doesn't really work, because if its not dynamic its not very useful in planning/design.
I managed to do what you warned about though, creation of 0 street width blocks (not through making a polygon first and going from that, but directly drawing 0-width streets), and it seems to work nicely. Don't see any problems with the subdivision either, maybe in some circumstances I will. But yeah, it would be cool if the block parameters could be defined in a rule file that would then be applied on any given polygon. That way the rules would be written down and saved somewhere, which is good if the intention is to transmit those rules somehow to official planning documents as well. Probably theres a bunch of technical hurdles, but I don´t see why it couldn't be in the CGA itself. Probably it would find other use cases as well, and then you wouldn't need parallel systems like Dynamic City Layouts. Or am I missing something?
Thanks for your answer!
-Jussi