What a great choice!!
It is to bad that people just keep using wat they want without compensation the planet for it. It was great to read that some of the states have set up controls on the usage of this plant, protecting it. As it does grow commonanly over the Eastern North America, I do not think any compensations should be made.
The purple coneflower is one of my favorite plants to grow! Even with the short seasons here in AK, I can start these inside in early Spring, I will get to enjoy them for a short time before the frost comes. As it is so cold, they do not make it through the winter outside, but I can dig up the roots and store them to restart!
I did not know the deapth you can use the flower for. How interesting that they are a natural form of antibiotocs.
As they can be grown freely I do not think they need to be compensated for. You had stated that they are mainly not used except by herbalist, so I would think they are home grown any way. I will be looking in to this flower next growing season! Maybe I can make use it of it other than in a vase on my