@Miller
Nice host and i found it for ~17€! It is a hard decision. I would buy both. But i will get the red card if i buy this two lights and the Q8 ‘( +parts) in one month.
The Dual host is an easy mod. The other one would be much more work (but thats what i like) but only RGBW.
I have to roll the dice.

@Miller
Do you know the MCPCB size that they use in this light https://www.aliexpress.com/item/Dual-Cree-T6-X5-LED-Flashlight-Bright-20W-2400LM-Torch-5-mode-Portable-Light-Aluminum-Alloy/32797901933.html?

Thanks!
20mm Ledboard is perfect! The only PCBs i could get for the MC-E LED is 20mm. And i have 20mm Tripple XP MCPCBs here for the UV LEDs.
Only the high VF is not perfect but it should be enough for real ~3w of 385nm UV light.
I have to order 10 UV LEDs on aliexpress (1 lot). But i do not need all of them only 6. So 4 leds are left. If someone is interested ( ~1,20-1,40€/led +shipping). I got the info that i can buy the leds without the aluminium pcb. So it is the bare led (so no need to unsolder it to use a copper dtp board). If there are enough people that want one i will order more max 20 (to avoide paying tax).
And i have to talk to tterev3 or someone that have expiriance with PCB layout. The leds i want to use have different current requirements than the normal MELD-X driver. And because there is enough space on a 26mm driver maybe it would be possible to implement the fet. . . . in the design.
If not i will make it work with a fet on a seperate pcb and with stacking 7135 chips.

Miller i forgot to ask for the reflector measurements. It would be nice if you could check it. So i can try to get a fitting tripple reflector for the UV led´s.

Nice so there is enough space to fit in the reflector of this light (https://de.aliexpress.com/item/Portable-CREE-Q5-White-Light-LED-Flashlight-Torch-Yellow-Light-Jewelry-Jade-Gems-Detector-Urine-365/32691728589.html?spm=2114.13010208.99999999.272.YUaCkr).
Its the only tripple reflector i can find that is small enough to fit in. To bad that a TIR will not work nice with the UV Light. A quad UV on a dtp board would be .
But without any optic or reflector its not a real option. If someone knows a tripple or quad reflector that fits the Wall-E light (https://de.aliexpress.com/item/Dual-Cree-XM-l-U2-Led-Torch-2-x-Cree-XM-L...) please let me know! ! !

The new modhost arrived. I am not impressed! There is a lot to do to make it work. Whats really concerning me is how to hold the driver. I do not like the spring solution. It is a loose fit.

A closer look at the switch assemble. To convert this to a lighted tail switch i have to make a new PCB.

The light feels really good in my hand too. But i instantly ordered new Glass lenses (to remove the plastic lenses) and i will change the switch part. I want to use pilotdog68 lighted switch design and make a new PCB that fits into this light. But i have to wait until i know if i have to use a reverse or if i can use a forward clicky. And going with 2 Nichia 219 should be no problem. But if i where you i also would work on the shelf underneath the ledboard. The contact area with the ledboard is tiny. I started to remove the ano. and try to make it as clean as possible. My plan is to mix 15micron fine copper dust with JB weld and fill up the 3-3,5mm deep cavity. And then make it as flat as possible. This should transfere heat much better than a huge blob of thermalpaste.

@TheMiller
Are you maybe interested to convert your tailcap too if i order new PCBs from oshpark to convert the tailcap switch construction into a lighted tailcap (As a secondary effect the internal resistance should improve dramatically)!

If you look under the ledboard you will see why it is not getting too hot. The leds are not able to get rid of the heat. And the resistance in the tailcap (the nice switch construction ) will not allow more amps.

And i did not ask if you where interested in a new driver. I asked if you are interested in a lighted tailcap (pilotdog68s design). Because he has no PCB design ready for this light i would make one (with a little help) and order from oshpark. But i have to order 3. So i will have 2 left over.

I build the original switch back in an made some tests. And as i expected the internal resistance is huge. After a few minutes at 5 amps the tailcap is getting warm (but not from the leds, the contact resistance in the tailcap is producing heat). But if you see the small weak contact point from the switch and the host it is self explaining why. The new design will help with that. More contact area and a screw that is pressing the pcb against the Aluminium ring in the host.

The tripple reflector with new Aluminium ring to fit in the head

The shelf is now nearly flat. The JB Weld + a lot of fine copper powder worked well but was a pain to grind!

Grinded down the Aluminium ring from the Momentary switch to make place for the new driver.

Both reflectors inside the head. On the left side there is not much left to do only put in the MC-E on the right side i have to make a 8mm thick spacer to make the tripple reflector fit (the Aluminium ring to make it wide enough fits perfect).

The beginning of a new switch PCB (because i do not have any etching solution left i decided to grind the copper of the board.

One step closer to get the UV tripple led spacer ready (core is 21mmx8 but i need 21×9 so i have to add another 1mm). All done by hand or my dremel. So it took a little bit longer than it would on a late

I like the work often much more than the finished product. Some small things can take hours and hours. Like this spacer when its done. Today new switches for my solder heat plate arrived. Now everything is here i can complete it (aslong nothing else burnes up). The first 12V 180W china PSU went up in smoke (at 120W load). Now a 450W PC PSU is in use. A little bit modding was needed, but i have a good stock on old PC PSUs so it cost me nothing. Only a bit of work. I think in the next few days i will upload a few pics (when its ready).