How to improve variable density (gradient) circle packing definition?

I am looking for tips and suggestions on how to improve this definition for circle packing in which the circle radii are defined either by a field or an image, a set of attractors, or other variation on that theme. Here I have included an image of a gradient.

I have seen a number of circle packing definitions using Kangaroo, but as far as I have been able to determine, the circle radii cannot be updated during the solve loop. 

This definition uses Anemone to make the internal loop accessible. 

I am sharing this definition with the community, and looking for suggestions on...

1. Improving speed/efficiency and smoothness
   1. Maybe there are clever improvements making use of delauney triangulation or Lloyd's algorithm?
2. Keeping the circles within the bounding region
3. Somehow auto-scaling the circle size range or number of circles in order to more completely fill the target region
4. Other tips or suggestions are welcome!

Feel free to use this definition for your own projects - but if you do, please share images in the comments below!

Thanks