I wanted to change the size of symbols in the symbol rings, as well as the central symbol. Regardless of the subring, I choose to edit, the symbol size input box appears to make no change to the magic circle image when I edit it, even to extreme values. 

Gotcha thanks for letting me know! There will be a fix for this in the next build (v1.0.1). Make sure you save your circle so you can edit it in the next build

Version 1.0.1 is out now!