Extend "Show other stacks/decks" to other editor features

V3.6 added images of existing stacks and decks, if they contain piece(s), to the GUI tool “Reposition Stack”. This is enabled via the option:
image

A similar ability would be handy in the Zone, Region and Grid editors.

Showing other landmarks, such as lines/dots for existing Zones, Regions and Grids may also help, as a separate option.