So I downloaded the .dll file and the multimod options tab pops up fine. I am able to use that but unlimited cannonballs and the modified flamethrower (what I really wanted) is unavailable. Any reason why this would occur?
I decided to remove this feature because I hadn't updated it in a while, and the game code had changed quite a bit. This made unlimited cannons and rocket flamethrowers hard to implement, hence my decision to remove this feature. Sorry about this