Allen,
Without commenting on the various details under discussion, I want to
raise a couple of questions: Why does SMTP "inherently" incur the
delay that you cite? While it is certainly true that general use of it
involves various sources of store-and-forward delay, I believe that
none of that is required, if a given sender wishes to accomplish a
"direct" interactive link to a given receiver.
That is, there is a big difference between protocol design and operational
configuration.
On the matter of user agents, you are simultaneously challenging the
lack of any UA's designed specifically for paging while also stating a
desire to allow Telnet interaction with an SNPP server. These sound
like competing arguments, to me. (However, the argument for allowing
Telnet access reminds me of the original arguments for the design of
FTP, 20 years ago...)
Dave