Second, the IPv6 SL mechanism exposed the fundamental architectural
discrepancy between the traditional application world viewpoint that an
address was a valid identifier,
The address *is* a valid identifier in the IP architecture. There is
no architectural discrepancy, only an explicit engineering compromise
to use the same bit string as both a host identifier and a location
identifier. Your repeated assertions that this is an invalid assumption
are incorrect. For better or worse, this is the way IP was designed to
work. The only invalid assumption is that it's acceptable for the network
to fail to support this model, without considerable re-design of not just
IP but the entire architecture.