Virtually all 2D programs have a "navigation: window available as a user option that shows the full screen and where the "zoom" on main display is located. That zoom outline can be moved or re-sized.
The navigation window is a handy tool to see where you are and navigate better/faster on screen.
Suggest that TFP and Envisioneer add such a tool as a new feature; and join the 20th century (yes nav windows have been around a long time)....now in the 21st century.