Well, it wasn't as smooth as 2pm, but my main line is working. It looks like the tech this morning did something because Sprint finally returned the first number to the third party center while I was on the phone this morning.

I called back at 5:45pm tonight and spent forty minutes on hold, and while I was on hold the first number got the text message and woke up. Now, the woman at tech support claimed that it happened on its own while she was looking for a supervisor, but I suspect that a query to the third-party system about the number might have nudged it along a little faster.