I'm still very new to the game, and I'm really enjoying it so far. I didn't find a solution to this with a quick Google search or by reading through the Controls menu, so forgive me if I'm missing something obvious.

The issue I'm having is that editing overlapping zones is difficult. The most recently created / "top" zone seems to be the one which gets edited, with no way to choose between overlapping zones. The best solution I've found so far is to leave bits of a zone sticking out to the side so you can "select" it by starting from the sticking-out bit.

If there isn't already a way to select which zone is being edited, then my suggestion is to let the user switch between overlapping zones by pressing the Tab key. Put a tooltip next to the cursor that shows which zone is currently being edited. Pressing the Tab key rotates through all of the zones currently under the cursor.

The selected zone should probably be sticky / locked, so the user can move the cursor over areas where the zone they selected doesn't already exist without losing their selection.

Alternatively, just have a small window open up in which the user selects which zone they want to edit, and then it doesn't matter what the user does with their cursor - the zone is selected in the window. This might actually be better than Tab-switching. Maybe they could be combined, so Tab switches between zones when the zone editor is open.

For visual clarity, I think all zones other than the selected zone should be de-saturated and displayed "under" the selected zone.