IS will training very fast because of elastic effect. Balanced players are way overpriced on the TL right now so if that gets up to say mediocre he will sell for more.
i don't expect it to be that fast, i have some small trainees who get IS training from time to time(and also should affected from the elastic effect), and they rarely pop.
Maybe you could train it a bit with training JS for Wings, or one vs one for forwards where i even had the feeling that it the height didn't affect it that much, even when i miss the big control group ;)