Comment 5 for bug 1498583

Patch v5 includes refactoring of the GUI in an attempt to group related options with notebook tabs as best as possible:

Tab 'Positional': original options
The 'Restack Direction' option was converted into an inline notebook with 2 tabs: Presets, Custom (arbitrary angle). Only the active (visible) tab is used for Live Preview and Apply.
Below the direction notebook are the remaining options (reference point of the objects' bbox) which affect all directional restacking.

Tab 'Stack': new options 'Reverse' and 'Shuffle'
This tab has restack options based on the original z-order, without taking the objects' position on canvas into account.

Tab 'Help': help text