From the computer program's point of view, the world is black and white. Either the mold is a great choice, or else it is unacceptable. There is nothing in between.
In the real world, we do have shades of grey. A 350 gr. 2-cavity in the standard brass block is definitely in the grey zone. It can be done, but it'll probably run on the hot side, depending on your casting style.
For that particular bullet, I believe you would be happier with either the 1-cavity block or the 2-cavity XL block.
Thanks for asking.