Even if you do mix the two properly and get a proper consistency, you gain nothing. Last reviews I read would rank the STG-1 and AS5 neck-and-neck, so you'd still get the same performance, if not worse. For these kinds of mixing, it's not a case of i.e. 1 + 1 = better, it'd be a (1 + 1) / 2 = same result.
Or you could create a tear through the space-time continuum, but what would I know.