For now, lets see how piciex’s XHP35 mod works out. He was able to buy the host with an additional battery tube for 4 x 18650.
If I were You, I would be careful and wait till I open the pacage and check what came inside. 
Hope everything fits.
That thought had occurred to me more than once. Please keep us informed upon receiving your package and of your progress. Do you have your XHP35 HI on 20mm DTP copper MCPCB yet?
No. I am still working on it with cutter.com.au
Probably I will have to buy a bare LED and put it on Noctingon myself.
Is it the same star for XHP35 and XP-L/XP-G2 ?
Cutter can reflow the emitter for you if you arent comfortable doing that yourself, but Im not sure if they supply DTP MCPCBS. Yes, its an XP footprint, so copper and DTP will be necessary to overdrive it to exchange the additional heat. I think 2.5A seems to be the max this emitter can handle before lumens begin to drop.
Any luck on a 25mm driver that can supply 12-13V @2.5A to the LED?
XHP35 DTP: http://www.cutter.com.au/proddetail.php?prod=cut2704
But I need HI version.
3.0A is the max: XHP-35
Driver: http://www.kaidomain.com/product/details.S024004 or Richard’s MTN-MAX (depending how long would it take).
Apparently there is no description of the output voltage of this driver?
Hi,
my build of a Trustfire X7 with XHP35 HD is almost finished. I used the LD2 Driver from LED4Power with 2,5A and 4S support. Sad but true the 4x 18500 batteries (same length as 3x 18650) are still on their way … after measuring Lux/Cd with this setup i will try to dedome the XHP35. I hope XHP35 Hi will become available from our modding Shops (MTN, Intl etc.), soon.
Greetings
Kenjii
From intl for sure not. They told me last week that they are not planning any XHP35. Did you use any LED centering spacer?
Hi,
no, i didn´t use a centering spacer. Had to try a couple of times until it was centered properly. But i have to wait for the batteries to check it finally. Just connected 4x 18650 with some wires to the head. And it is damn bright 
Greetings
Kenjii
Is there many space between the reflector and 20mm Noctingon wires pads left?
Hi,
no, there is not much room left. I soldered the wires extremly flat to get as far into the reflector as possible. I soldered some copper braid to the ends of the wires to make it more flat. I additionally reflowed a second noctigon star (grinded) under the MCPCB to set the LED a bit higher. I think it could be needed to open the hole of the reflector a bit. I read in other threads that an ugly ring around the spot can be avoided by that. But i will see when the batteries arrive.
Greetings
Kenjii
Hi,
i did a short test with 4x Panasonic NCR18500. The batteries fit perfekt into the light. I measured 132 Klux@1m/Kcd (perhaps ~250 KLux with XHP35 Hi?!?) with LD-2 Driver and 2,5A. Massive Output. I still have a bit of work left with the light. It shows that ring around the spot an i think i can get the solder points even more flat.
Greetings
Kenjii
Would 20mm star be OK for this pill?
Hi,
20mm star is perfect for this light. The star can be screwed onto the pill. As i wrote before, you have to place a spacer under the star to lift it up a little bit.
Greetings
Kenjii
I am not quite sure about the spacer. Wouldn’t this worsen the heat conductivity betwen the LED and the pill?
Hi,
that´s because i soldered the two stars together for best possible heat transfer under these conditions. Better would be without spacer but then the LED is not at the focal point of the reflector what means losses, too.
Greetings
Kenjii
If you cant find or make a copper disk, you can heat a 20mm noctigon or sinkpad with a torch and burn the insulative layer and traces off. Heat only to slight pink glow and then quench in water. This can take more than one time to get it completely clean. Then lightly lap each side with fine sand paper on a flat surface and you have a perfect spacer. I didnt solder my MCPCB to the disk and lumens dont plunge as the light heats up, so it appears that soldering them together wasnt mandatory with my mod. Of course, soldering them together would be the best way to assure proper heat transfer.
If you solder them together, then you dont need to lap it with sand paper. 
True, but then future emitter swaps would take more time and effort.