I see no reason to not run it in karts (other than it will bounce you in fuel tech every time -- seen it happen MANY times.)
Alcohol is very corrosive by nature. Anyone running fuel injectors knows this. It eats into brass, aluminum, and magnesium (especially if it's allowed to set on it for a long period of time.) The injection on sprint cars have historically been mag, some have more recently gone to aluminum. Hard anodizing or plating prevents much of the corrosion caused by methanol on bare metal, but things like intake runners are still bare and show the effects of running methanol over time. The upper end lube certainly helps, and it sure helps on fuel pumps, especially cam driven pumps like we use on the sprinter.