Guess I didn't make my intention clear.
I was thinking that this would basically act as top-up water. Brew a higher than desired SG, and use the no-chill container to store, sanitized, ice water. Perhaps not ideal, but it may be another way to maintain hop flavor and aroma in a recipe.
Looks like I'll raise this one from the dead.
I was considering a different method of using the no-chill method and the cube in particular for late hopped beers. Boil brewing water, with salts added, put it into the cube and allow the vacuum to develop. Put it in the freezer on brew day, brew...