Hi Val,

1) dynamic composition - building something from smaller parts.
2) visual decomposition - breaking something down into smaller visual parts.
3) syntactic decomposition - construction rules for identification.

I've read a lot of the Unicode documents: official documents as primary, technical notes as secondary, and critics as third.  I've interacted with several types of Unicode people.  I believe I have a good understanding of what Unicode was in the past and what Unicode is now.

I know what Unicode says on paper, but I don't know the inner circle of the committee process and I don't know the existing font technology.

It is impossible to have a perfect solution for Unicode that satisfies every principle and ideal.  Any encoding process will begin with 1 major principle, and everything flows from that.

The Unicode experts, from day 1, started from a different founding principle: they understood visual decomposition.  I tried to explain my syntactic decomposition, but was told it would never make it through committee. 

For the past 2 years, I've had a series of compromises with the Unicode process. I'm only happy about the first compromise.  We encode the symbols before the script.  This compromise still seems to be holding.

The preliminary Proposal incorrectly explained the syntactic encoding design.  A committee member noticed the disparity and asked for clarification.  A problematic compromise was suggested and quickly adopted to continue the committee process.  Just last month, this compromise failed and there is no proposal design.

For SignWriting in Unicode, the idea of visual decomposition is in the initial stages.  They have not met reality.  They do not have a font and they have not processed text.  I do not know how quickly their encoding will mature.  I'm assuming they'll have several intermediate phases, rather than just throw something together to submit in February.

Visual decomposition may integrate well with existing font technologies, but visual decomposition is a subset of the higher Unicode principle of dynamic composition.