Simple TclOO and static class variables

The discussion of class-side slots for TclOO is instructive in light of Carl Sassenrath's blog on defining "simple" in Rebol and in-the-large.  But in the real world things are not so simple.

The TclOO architect offers his snippet from the view of the code internals of his framework.

Tcl 8.6 is in a slow beta while Rebol3 remains alpha - and in fairness TclOO was already a library for 8.5

A Curl (as in www.curl.com) architect in Boston once gave me his take on Tcl ... but again, in fairness, not having access to the internals of how mixins are implemented in Curl ...

The simple view: use traits where they are useful in maintaining separation.  Much harder: to get a project to adopt traits effectively (e.g., non-HTML output for Smalltalk Seaside or Scala Lift.)  Perhaps not possible: getting traits into ObjectIcon.

Anecdote: the Avro Arrow had a compontentized "open-bay" in its belly - long before the ISS universal docking spec.

Question: is re-motoring aircraft types always "simple" ?  DC-8?  And new wings for C5 Galaxy?  Will the Shuttle engines be re-used?

Question: Should the Canadarm2 have been coded in Erlang or Oz instead of Ada? Erlang would offer X, Oz X, Y and Z.  But for Ada there are tools and staff.

What is the "simple" approach to handling text in the age of Unicode?  My test candidate: Octavio Paz' "Blanco" as the intended "dynamic text".