To make clear what I mean I took a photo of both the GT and my Boss. The first photo is the GT. It clearly is brighter, but there is a lot of light around the hotspot. IF it was possible to concentrate that light, it would improve the beam.
This is a beamshot of my Palight Boss with a dedomed XP-L V6 1A. There is very little light around the center. If only I could make my GT throw the same.
@ johny723 ……. OK…… I think I now understand what you are saying. I do not think this is possible with the GT reflector / LED setup. It was designed to spill this amount of light so as to be a more “”useful”” light. 
This is what I remember anyway.
Thanks… i bet dedome xpl will give some green tint…
I measured my friend’s GT too only swapping the head and his got even worse numbers than mine. The batteries were fully charged and his GT only pushed uot 894 Kcd. Mine does 980 Kcd again but interesting the different results at different distances.
Mine:
10m: 980 Kcd
15m: 969 Kcd
20m: 928 Kcd
25m: 929 Kcd
His:
10m: 894 Kcd
15m: 857 Kcd
20m: 856 Kcd
25m: 877 Kcd
I think it is mostly a focusing problem so I will try to open the head and try enderman’s focusing method
Let us know what the results are.
We both got our GT in early March and they travelled together according to changes in tracking had only few minutes differences between the two lights. So I think they are same manufacturing batch got not so throwy. I need to get a strap wrench or something and then try focusing.
I managed to open my GT head with a leather belt 
I printed out Enderman’s focus checking circles with the 3 square. I have still my friend’s GT too so I checked both. Mine was good for about 1m distance and then started to seem over focused. The 3 square moved to the center. At 7-8m the 3 squares almost completely overlapping each other. That is why I got the biggest numbers at 10m because it was focused around that distence. My friend’s GT was even worse. As we seen in the intensity numbers too. So I need to sand the centering plate thinner. I needed to go to work so tomorrow I will measure centering plate thickness and sand it down a little.
could you take a beamshot before and after sanding the centering plate?
you don’t see it on a beamshot. Maybe with the focusing templates you can see the squares but with naked eye I don’t think so. But I will try to make photos.
I meant a photo that compares hotspot of a stock vs sanded centerpiece
I can try but you will don’t see much I think. These are not huge differences just hunting for the perfection. If I can manage to focus better and make 1100 kcd from my 980 kcd it is not what you can notice in a few meter wall beamshot.
Just tell us if sanding down the centerpiece improves the hotspot at larger distances. Especially if it can remove the corona and make the center brighter.
Sure I will report results 
Thanks!
I have some results! 
My theory was a bit wrong. The centering plastic wasn’t too thick. It was thin. I sanded down from 2,5mm to 2,33mm and it made worse. I only got 874 kcd from the stock 980. So I started placing kapton tape stripes to the bottom and about every 0,1-0,15mm added I reassembled the head and went outside to measure lux at 10, 15, 20, 25m.
Today’s last result was 1100000 cd at 20m with 3,17mm thick centering plastic. This is not the end and I have pics and a lot of numbers. The interesting that as it was getting better the highest number moved to the bigger measuring distances which I think is good because the beam is more parallel and forming the hot spot farther is good. Tomorrow I have a lot to do but I think I will add some more tape under that centering piece and I want to find the best focus setting. And I will post all the pics and numbers when Im done.
Stay tuned!
Interesting, thank you for sharing 
Very interesting results.
The latest batch of reflectors was made by another company (which is why there was no shipping delay this time). It is possible that the focal length has been changed slightly. It would line up well with the XHP70.2 I built.
I used a 4.25mm centering ring on the first light I built and it had no dark spot but it took almost 5mm to get the same results with the new one.
Plastic shims for under or on top of the centering block. Mine is shimmed at 3mm thick overall, my other GT’s reflector was better so I swapped them. Dark hole in the beam 3.5-4ft. off the wall.
After running about 30 Minutes on Turbo on a sunny afternoon
I tweaked the focus a little bit but it is still far from perfection. Measured 1.7 Mcd-2.3Mcd.
Regards
Kenjii
Today I went up to 3,42mm centering piece thickness and got 1174500 cd.
but the hot spot started washing out so I think the optimal thickness is between the 3,17mm and 3,42mm. Now I need to sleep so I will try the last steps a few days later when I have more time.