As for a possible group buy on the RoMiSen RC-3114 :
I bought, and received, a Romisen RC-3115 (a different but similar light) from Tinywind and here's a short impression on that one that will give a good idea about the light of the group buy. The RC-3115 is basically the same flashlight as the GB light, same build, I assume the same driver, but with a warmwhite+coolwhite XP-G2 (=kinda cool too, and the tints are good: cool=not too cool, and warm=nice 'n cosy :-) ), and a different bezel:
As you can see, it has a 'P60-style' pill which has its influence on the performance (pill floats inside with no real contact area with the body; =bad heat path, and the stainless steel body does not help either). The tail has an Omten switch in a plastic holder, one of the leads lightly pressing against the side by its own springforce, the other lead is pressed against the battery spring (not the best design but for 1.25A sufficient, and for modders: I'm sure you can swap it for a standard 17mm switch board without much problem). All sizes 18650 batteries fit. The UI is basic: reverse clicky, click for switch on, half press to toggle between the emitters (no low modes). The current to the emitters is about 1.25A, the output is just over 200 lumen OTF for cool, a bit under 200 lumen for warm (so not that great for today's standards for single 18650 lights), the beam shape is actually very decent for this double reflector: a nice defined round hotspot with a bit assymmetrical spill, the spill will look better without this conus-shaped bezel.
Problem: the emitters will not live happy lives with the extremely bad heat path to the air: it will become bloody hot in there, even at 1.25A. This no problem for shorttime use, but after a few minutes I can see problems arising.
Thing to do still: make a picture of the driver, and do a runtime test to see when the light fails because of the heat build-up.
Longterm project: do a nice mod with this light with a PC-amber XP-E2 + 80CRI XP-L and custom driver.
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Now for the group buy light: there will not be a sample of the group buy light with the 365nm led in place because RoMiSen will only start doing a production run of this light if Tinywind agrees to buy them off them, and Tinywind wants a minimum amount of promised sales of 200 units before they order the lights, and then they can offer the (pretty good!) GB price of 12 dollars shipped. This is a pity, but IMO understandable.
So I can tell you guys about the build quality of the light and the performance with white leds, but the quality and performance of the 365nm led will be a bit of a gamble. An educated guess from my side is that the Vf of the UV-led is higher than the XP-G2 and so the current will be lower than 1.25A, which is all too well because 1.25A without a DTP copper board is pretty tough on a 3535-size 365nm UV-led. In other words, the performance could very well be ok.