I'm not using the zone frame from the minimap at all (i use the titan panel zone frame, because it have the ability to print coordinates in chat with a single click).
So maybe an option to disable it entirely (the zone frame AND the red cross) is easier to implement ?

See how ugly it is: https://imgur.com/a/1O1LTAH

that one is a bit harder because the frame that shows the zone has the button, maybe it can be clipped though