Actually, Increasing/Decreasing pixels should not change when you deselect a layer. Layer preview modes should allow you to see which parts of the image are going to be brighter or darker at a given scale after applying the process as a result of modifying layer parameters.
However, your report has shown several important bugs in multiscale layer preview modes:
- Preview All Changes does not work (white image always).
- Preview modes ignore layer parameters (bias and noise reduction).
- Preview modes ignore the currently selected layer.
In summary, these preview modes are not working at all. I'll try to fix this issue as soon as possible, thank you for reporting.