Since the only smaller shim I had from the Motive Gear kit was .021, I decided to try that one.
.021 shim, .008 backlash
The drive side is not terrible, but the coast side is way in the corner. Before I tried another shim, I decided to reduce the backlash, just to see if it made any appreciable difference in the pattern.
.021 shim, .005 backlash -- no appreciable difference in the pattern