If I'm giving someone a pie in a pie plate, I'm not expecting to see the pie plate again. It's part of the gift.
(that's why I stock up on Christmas cookie tins and pie plates in the after-Christmas sales - to be ready for the next season)
I don't expect the container I give food in to come back. Except in some specific potluck situations (office etc).
I'd be insulted if the pie plate came back. I can't even imagine what I'd do if it came back - with other food in it. It would probably start some kind of oneupmanship war. I'd have to make something better, deliver it with the pie plate, and a pie server

or some napkins (or would the napkins be part of the third round?)