There have been one or two times that I’ve already had a reservation for multiple days at club level and then added a day before or a day after the main reservation for a standard room and was given my club level room or allowed to remain at club level.
In the Boardwalk, we had to change rooms and were physically on the other side of the club level door, but we were still given access to the lounge for the remainder of our stay.
I have also been upgraded at the Contemporary from the wing to the tower, although I was still on the Bay Lake side and certainly not club level.
We’ve had a few other middling upgrades, but nothing special.
As for discounting the upgrade, I honestly don’t know. I think that’s going to be something that is case to case.