The "Set as Background" option has been updated in AudioLabel 5.00 (Build 6) and now works similar to AudioLabel version 4.40 (with a few changes). With the new version, if you double-click an image on the toolbar, or press the "Set as Background" button, the background position is set based on the "Background Overlap" option in the Print Dialog, or Save as Image Dialog. Furthermore, if the "Set as Background" button is pressed more than once, the background position will advance to the next "Background Overlap" position. Once the background position is set, double-clicking an image on the toolbar will use the existing background position. I know it sounds complicated, but it's quite easy to use in real life.
Thanks for all the input, and please let us know if you have any other thoughts on this.