I used to use Chinchilla Minimap, which did pretty much what this addon does, but with the extremely useful addition of letting you set a range circle in the minimap. This let you see, clearly, just how far out of range you were of a target without having to constantly watch the attack buttons' color. Also excellent for keeping in range of heals, if you set them as a focus target.

Sadly, the maintainer of Chinchilla has apparently forever quit WoW.
Any chance that you could borg the relevant code from Chinchilla into this addon?
I'll be watching with hope.

Please attach some screenshots demonstrating the feature

I can't show Chinchilla doing this because it no longer runs at all.
Here is what I am looking for though. Adjustable range circles, saved as pref settings, which can then be changed out via hotkey.

I used 100 yd for gathering, as that seems to be the detection range for nodes. With a range circle on minimap, one is able to be sure the entire area is swept for active nodes.
For general questing and dungeons, a 40yd circle works well, that being the most common range for casters & healers.

If it would be possible to have two range circles, that would be excellent, especially for short ranged casters such as Evokers, who presumably still want to stay in range of heals.