Update
Called web support again the other day - it took them a while to understand the problem, and ultimately I let them use my MP account and my password so show them that no availability shows up when searching for standard award availability to/from SMF. Got transferred to another person who said that this was an ongoing problem and that it also happened with BOS and BDL. No time given for when they think they might get this fixed - I'm certainly not holding out much hope for anything soon.
Very frustrating that I can't check upgrade availability to/from SMF on-line. Grr.