Probably not necessary.

You're dead center on the mini-map.

Test it by going to the same spot where an NPC is standing. When the NPC has a yellow ! it's obvious to see where it (green) is on the minimap even if a ton of players are around. I don't know about other devices, but on my iPod, that is exactly in the middle of the screen.

So, whether the minimap is zoomed all the way out, or all the way in, it's fairly easy to tell where you are on the minimap.

If you need another reference point, that's right in the middle of your name as well, if you have it displayed.