Today at YUL domestic regular check-in with kiosk-printed Zone 5 YVR-YYC BP in hand... completely empty, many agents available. I walk up the first to call me and the following transpires:
me: "Hi, I'd like to buy a last minute upgrade. This is an X fare Aeroplan booking."
agent: "Ok, let me see." Grabs BP, scans it... huge scowl on face almost immediately followed by "Mr. Cargo, _YOU_ know Aeroplan bookings cannot be upgraded" and hands the pass back.
me: "I believe it is possible for me to purchase an upgrade no? Not an eUpgrade or anything special, just pay money and buy the seat?"
agent: "Under no circumstances can an Aeroplan booking be upgraded. It doesn't matter what you call it."
... I take a look at my small carryon, then glance at the Zone 5 on my BP ...
me: "Ok... " Hand BP back to agent "I need to check in a bag. Let me ..."
agent interrupts: "How will you pay for it? It'll be 25 dollars"
me more sternly: "get my card. And NO, it will be 28 dollars and 74 cents after taxes here in Quebec."
not another word spoken throughout the rest of the transaction... print, label on bag, on belt...
me: "Thank you for your help!"
Later I wander through the airport trying my luck at the Air France lounge, the VIP lounge on the basis of other cards/elite status... In both cases being very careful to point out it was a domestic flight on Air Canada. To the credit of both lounges, both researched the rules thoroughly before telling me no in a very polite manner, both stating that they can only allow International pax admission.
Wandered back towards Int MLL and thought I'd chat with the agent about the LMU again.
me: "I have an Aeroplan booking on which I'd like to purchase an upgrade. Is this possible?"
concierge: "I'm pretty certain yes. Let me see... line 1 (pointing to the screen)..." taps the 1 key on keyboard, swings the monitor around and says "See? $648 after tax."
... transacted with very pleasant conversation redacted...
And I write this sitting in the International MLL in YUL.
Now I'm out a bag charge, I have to wait at baggage claim when for sure I'd get overhead... Apparently LMU isn't something AC trains agents to sell, and would rather eup waitlisted cheapeners?