First of all: This is a bug, that I already fixed for the next version.
Nevertheless I am very much in favor of changing backgrounds to static ones. I already said so
in the previous thread, which however did not create a lot of feedback, so the issue was forgotten.
As the person who has to implement the change, I would like to add a few more comments:
1) I will
not make this an option: Either all backgrounds are static or all of them move like the current ones.
2) Too small backgrounds should not be a huge problem, because we still can use the paving algorithm to extend them to the full window (not level!) size.
3) Regarding too big backgrounds: I wouldn't worry too much. The width is usually low enough that the whole piece can be displayed in fullscreen with 3x zoom. There are some pieces that are higher than the usual screen height, but already now they have two problems: First of all they won't get displayed properly on levels with default height either. Secondly they are usually "sky over earth" type backgrounds, which would look extremely ugly if they are paved vertically. So it might actually be preferrable to see only a part of them, instead a paved version.
4) At the moment I am not sure how to handle zooming with static backgrounds. I tend to keeping the default zoom, i.e. not zooming the background image at all. But that begs the question: What should be the default zoom for the background image? The initial zoom for the level perhaps?