Is is possible to copy savefiles (if that is a thing) from one installation to another?
I would like to know the same thing. seems no one has answered your question which I think is a good question. I do not want to loose my maps on an upgrade.
Yes and no
the save will break if it finds an unexpected parameter like a new save feature. but its usually on only new things. So chances are your objects will load, but maybe not your camera or sky settings, depending on how far back your save is from