Great news!
I just made a change to a VERY simple itinerary: YUL-FRA-VIE, VIE-FCO, FCO-FRA-YUL, changed return to FCO-IST-YUL. No date change, no stopover change, nothing. Agent charged me $250, refunded around $120, all is well (2 people). No mention of increased mileage.
... except I am missing 40K miles in my account, and in "my rewards" it says the reward was 220K miles, and I have a 2x90K refund in my account now.
:facepalm: :facepalm: :facepalm: :facepalm: looks like I have to spend time on hold with Aeroplan again.