An in-between of stock and the tuning block is to add a couple spacers (and longer bolts) under the bracket. Cheaper too.
True. BTDT.
But, putting spacers in causes the two brackets to be at a slight angle to each other. This puts lateral stress on the (longer) bolts that go through those spacers and there is some small amount of flexion that may occur during windshield movement. If you look at the Rifle tuning block it not only spaces the bracket halves apart, it also offsets them and provides the required angle:
Now... many folks will pipe up and tell about how they have installed various spacers and longer bolts and run them successfully for many zillions of miles. But, there have been some cases where the longer bolts broke, which could be rather a bad thing while under way. I don't mind spending $50 for a better and safer windshield solution for my $10k motorcycle.