Thanks this is good to know, but not sure I want to risk losing that Biz saver award. Too bad the sale isn't producing a nice number for just the one way over. I was able to grab that biz, not when I tried 320 days out, but rather on a chance fluke time I checked a few months ago on the AA site, EF didn't send me an alert either. Maybe it was just the case you describe. Someone put it back just as I was searching. the only Biz that occasionally come up are HA and only one, never two spots, but I'd rather the direct to DFW anyway.
As far as the saver from economy to Business. I'd imagine they would want to redeposit the miles I used for her, cancel her ticket, reticket and take the new more miles out and I'm assuming another tax.