OK... here's the answer to my own question.
For annual renewals, you need to
1) Update the employment reference (you extend the date of employment if you haven't changed jobs or your employer submits an entirely new employment reference if you have changed jobs), and
2) Submit a reference update, which is really just another reference, which can be *ANYONE* (except the prohibited family member) in the world so long as they are licensed. Of course, you could always use one of the five you already submitted with the original record application.
This isn't as big a deal as I feared because 1) is easy and 2) can be done by anyone (hey, even someone here on EB if you trusted them enough to recommend "yes" and not rate you as "poor").
I'm also told that once all the application information is received, it takes about two or three weeks to complete the review. If all is well, you'll get an e-mail.
So... bottom line: I still think this is a good idea for anyone that thinks they might change states.