wrote:

[snip]

Indeed it seems like the specification is really the
only hard part here, yet I don't think anyone in this
discussion has seriously addressed that part of it yet.)

Duh, me again -- I suppose one could say that the
exact specification *is* Kim B's spacetime diagram;
so in that sense Kim did address the specification
seriously. However, the pitfalls that I wrote about
are nevertheless there when one *talks* about this
spacetime diagram. And as I pointed out, I do not
think even Kim is getting that talk 100% right.