Dear author, on one hand, thank you for your useful mod, but on other hand...
Why making stone non-configurable? You even say in description, that someone can make mode extremely OP, but on other hand you fix some amount for no (objective) reason. If one wants to not get (much) stone, he currently still can setup entire settings to still get extremely low amount of stone (for example, use 1000 frags -> 300 of A + 300 of B + ... + 3 of stone in recipe).
On other hand, if I want to have adequate custom ratio, I can't do what I want with that fixed amount of 3 stone per operation. I found it very strange and sad, especially while main aspects of your mod are good, exactly what I needed and even more. I highly recommend you making stone customizable, it will make your mod perfect.
I understand what you wanted to do by that way, but current implementaion makes things disproportionately bad IMO, just not worth it...