In fact, I usually do not ferment on grains, however, you won't have any diastatic power calculation issue with this yeast.
I'm now fermenting on grain, and it isn't a big issue, providing your mash tun/fermenter is large enough.
Well, Saltbush Bill gave you an incomplete answer...
"You don't need to mash anything when using the Yellow Label starter of liquor making yeast”.
Indeed, but in Rome do as the Roman do, and Chinese Baijiu is based on steam cooked rice.
There's no free lunch, if you skip the mashing process, there's a drawback, the fermentation process takes longer as Angel Yeast themselves write it on their website, 4 to 8 days in one situation, 8 to 15 in the other, plus more yeast.
You are right, mashing grains does not only gelatinize starches, but also enables the development of specific flavours.
That's one of the reasons why I use whole rice, with husks, in my Local Whiskey Recipe.
Here:viewtopic.php?p=7803845#p7803845
You also may have read posts related to bad smell, in other words, contamination.
That's another reason why I steam cook my rice, and gelatinize my corn, keeping the T° above 80 °C for how long the gelatinization process takes (+/- 60 minutes).
If you have a large quantity of corn, α−amylase can be added at the beginning (0.02% w/w of cereal) to reduce the viscosity (avoid a big clump of polenta). This is what I usually do and it helps. (The Alcohol Textbook, page 16)
I'm using stainless steel vessels, and this makes a good sanitization possible and easy.
In a nutshell, why should we mash our grains with YLAY?
1. As you wrote, development of flavours;
2. Shorter fermentation cycle than with uncooked grain;
3. Sanitization of your equipment.