Ok, my decision to slice the dome off was kind of made for me. I was trying different focus points and at some point something got on the LED and started the dome burning.
So I went ahead and sliced the dome off to get rid of the burn. Not my best slice by any means, my Soldering iron died today (yay, now I have to find a replacement that will not cost a ton and get here this year) so I could not remove the mcpcb from the light and it was hard to get the razor in the right position.
Still even with a less then perfect slice the results are way different then I expected. I thought the days of 50% gains from de-doming were behind us?
Turns out they are not.
With the dome on I got 450 Kcd for 1337m of throw 
With the sliced dome I got a stinking 700 Kcd for 1680m of throw!
So the GT now matches the best throwers on the market with 2x the lumens and an XHP70.2 LED!
Now for the results.
I am not sure what the lumen loss was as I can’t test the GT all put together but you can figure there is some loss, still over 6k if I had to guess.
The darkspot in the hotspot has been virtually eliminated now, only if you really look close will you notice it.
The only con to this is the tint shift, the tint shift around the corona grew significantly in both size and harshness with the slice.
Not unbearable but noticeable now compared to before when you could ignore it. White wall hunting is not it’s strong point like this.
Now it is possible some refocusing could improve this, it did with the domed emitter. Or using a cooler LED for the slice, a 5000 or even 5700k could work better but I don’t remember seeing any 5000k high bin XHP70.2’s in my searching.
I will play with the focus later and see what it does.
Wow, I am still amazed at the results, I didn’t even expect this much out of it. Goes to show what kind of performance you can expect when modders get ahold of this thing.