I used the chart and the "tools" I purchased to open up the orifice a couple of sizes. I went up to #63 for 9563 and there was improvement. The grill heats up faster and gets a bit hotter more quickly. To access the orifice all that was required was removing the burner tube, fold out tray and handle on the regulator side. Careful, easy does it use of the drill bit and vice from micromark worked like a charm. The vice did not clamp down on the bit too well but it got the job done.
For an 8K BTU unit the #65 (8557 BTU) bit was tight and probably opened it up some. The flame is still completely controlled, and uniform. The low setting provides a good low setting still as well.