Originally Posted by Carbon
With just 3 bolts the grate might lift at one end when applying heavy brush pressure when cleaning which is no biggie. You also need to be a little careful when loading and unloading food off the grate, making sure one side is not too heavy.
Having said that I plan on using just three bolts on my upcoming build.
I have 3 in mine and never had a problem. I also remove the grate for cleaning. Not saying you won't have any problems either, just that I don't.