Slightly off on a tangent, but is it better to add grain the to the MT first and then underlet the strike water? Mt last(and first) AG brew I added the strike water and then dumped the grain in as I stirred.
From my own experience, watching a few different 3V systems and discussions on here I have found
adding grain to water results in potential dough balls, (I've seen a few different shake n pour n sprinkle methods) hence you need to ensure you mix ALL the grain to eliminate all of them.
adding water to the grain from above (overletting) also often results in dough balls
adding the grain and underletting you eliminate nearly all dough balls and a quick stir is all that is needed.
The bigger the system the worse this becomes, imaging digging through 20 odd kg of grain trying to get rid of dough balls.
But with a single batch system, stirring as you slowly sprinkle in a few kg of grain will work.
All will work ok, as long as you stir to eliminate any dough balls.