Supertigres not designed to run on nitromethane?
Interesting theory...........but wrong.

If an engine has too high a compression ratio, then high nitro could be a problem. But that's not the case with the ST2300. Engines also tend to be mre reliable on higher nitro. You get a wider practical needle setting the more nitro you use. Also the higher heat of the nitro makes it easier to keep the plug hot and the fire lit. I've got a very reliable ST2300, and I only run it on 25% nitro. And yes, it's costly.