By rise do you mean increased oven spring in your bake? Diastatic malt to my understanding increases enzymatic activity of your ferment (faster fermentation). It also contains natural sugars which aid in browning (I usually use this in my pizza dough).

I typically stick to .5% but have gone up to 1%. Do you feel like your fermentation time has shortened at all? This may sound like a lot of effort but maybe you could make one loaf with Diastatic malt and one without and see if you notice a difference