I understand what it's supposed to do, and in a "Spokes" map it seemed like a reasonable purchase for its very low price.
Ah...Taking a much, much, MUCH closer look, I do see the green/yellow change, but it's almost impossible to see against a lot of planet backgrounds, or if there's any glare on the screen. Also, if you're zoomed out and have a lot of turrets around your wormholes, that means you have to zoom in all the way. On a "Spokes" map...pretty time consuming to check them all. A much better implementation would be changing the color of the wormhole *name*, or making the name flash.
I've been playing on and off since the game came out and I've never actually used the minimap. So somehow I read 'minimap' as 'galaxy view' in the description... Still, shouldn't the galaxy view get some interface love for the warp scanners too? Flash the wormhole it's coming through.