In short, when iconicity is abandoned as an effective measure, in favour of visual complexity and compression, the second problem identified above is also dealt with. That is, whether or not an observer perceives a loss or maintenance of iconicity across the full history of a writing system is of far less relevance to whether the writing system—both the individual items and the set of items—is becoming more or less compressed over time, or remaining stable.
Emergent writing and the Vai script
[This bit has been cut and paste into the document 'Writing evolves towards optimal simplicity'
Stray notes
functional pressure might be related to preservation of complexity
-do we get to Tamariz level complexity, eg take all the chains that start above forty and show that if we do see decreases. Ie, what goes up must come down. It would make a point about point of departure.
It works in practice but will it work in theory.