I also noticed that it was below the cree spec for this bin. At 1A I measured 320 lumens so about 15% lower than the spec’ed 365 lumens.
The measurements I did to investigate the XPG3 (The XP-G3 and the mystery of the disappearing luminance) are relevant here. The XPG3 has the similar flip chip design. I measured the candela above the die just sliced and after I scraped all the phosphor from the area to the sides of the die. As in this measurement the candela above the die is proportional to the total lumen output. There is 15% decrease in output when I scrape all the phosphor off, allowing the blue light to escape out the sides. That situation is similar to with the XD16 by itself or surrounded by other XD16s, so I might expect a 15% increase in output when n in array form.