It looks like I can now book a comfort fare on the Avion site. All the same options appear as on the AC booking site. My previous strategy of "I want a comfort fare, but the site doesn't have it, can I have an authorization number" will no longer work.

I think the only remaining option for a statement credit is to book some Y fare one way, and a J fare the other, by asking for a multi-city booking. I tried that, and the Avion site just spat out the return flight's booking class (not the two different ones I selected). So I could conceivably call in and say that I can't get what I want on the site.

Does anyone have any success getting an authorization number with this newer more sophisticated Avion booking tool?

Despite best efforts to move away from Avion, have accumulated enough points that this is of interest for a flight sometime next year.