[…] reaching for it as evidence that I might be confused is such a stretch […]
I suspect this statement is the source of all of this. When I sent this comment, I wasn't trying to do some "gotcha". I thought we were, in a sense, investigating together through documentation to try an find the right answer to the question. From my perspective, you provided an idea of what it could be, and I was trying to work with you to narrow down if that was for sure what we were looking for by providing some documentation that I came across. I wasn't trying to insult your intelligence, or belittle you or your help. I simply thought we were brainstorming together.
I think that's a fair point! At any rate, I do agree with you in that I think that users should be completely portable for a truly sustainable federated service.