All your questions are answered in this thread.
I simply swapped mcpcb, no reflowing.
/\ Thanks, Jason.
Same here,but I have 219b sw35 in mine, epoxied a magnet, also the convoy S2 clip fits well.
I use it for around the house plumbing work and beautiful rose colored walks with dogs
I’m preparing to buy my second light of this family, D10 this time.
Reading about how these are manufactured by multiple companies and how quality varies I decided to search for a good variant.
I’ve read of one difference that allows to filter out at least some bad ones - they have bad holders and the light is not secure in them.
Some bad holders have a hole in the middle, the bad ones have a nub like below:
Mine is good and has a nub which confirms the observation.
So I went on to search on Ali to see what was there. I hoped that I could find a brand that would be consistently good.
I see 2 major brands, Boruit and Sanyi as well as many unbranded. Reading reviews I see that both brands have seen complaints about holders that wouldn’t secure the light properly.
The seller that I bought my light from (Boruit Official Store) also sees such complaints, so ordering there again does not warrant quality. 
Any suggestions on how to avoid the lottery and get something consistently good for a good price? And I need primarily a host, so Sofirn price ain’t good and I’ve heard that Sofirn holders are not really good either.
I see some customer information in the Boruit Official Store sale advertisement link you posted earlier but, would you mind sharing any other details? I wonder how hard is it to modify, emitter and driver wise namely.
Just went and confirmed mine also has the nub, and it seems the hold it in there pretty firmly
I haven’t hard yet, but at least uneasy.
The bezel doesn’t come off and is likely glued or held with a press-fit shim. 
And I should note I’m bad at opening lights other than the easiest.
Hate those clippy mounts, and prefer the rubber rings like the original RJ02 has/had. Secure, yet easy-on/easy-off when needed.
Mmm, maybe you can try dipping the thing in some white spirit or turpentine, that should dissolve any glue in a few hours (white spirit will damage any o-rings, be warned). 
There is nothing interesting inside anyway
Thanks a lot for the video.
Simple…bit I haven’t tried that before.
Now I did - and it didn’t work, even with significant force, I only managed to scratch it badly.
The interesting thing inside is LED which needs to be swapped to make this a really good light.
Will get some turpentine, thanks Barkuti!
Will any colourless turpentine do fine or should I seek specifically white spirit?
there is no way to be sure with those inexpensive brands, it is always a lotto. but in this particular case, it is certainty 99,9% you will get new holder, they seem to stop making first gen holders
i stopped using all my oem holders and bands, i print my own, and i use 35-40mm bands. for d10-25 as well as zebralight and skilhunt.
if you can print, you can find stl in this thread, [Review] 77 Outdoors D25 Headlamp (18650) and it is tested and it works great, just print it on the side,
i also designed my own holder for d10-25, as well as zl h600. i have no way to post stl here, not i have acct at stl hosting sites, but if interested pm me i’ll email you stl.
btw, you can heat up 2nd gen holders grips and bend them in tiny bit, and it will hold just as good as 1st, i tried it and it worked great, using a construction heat gun, but i set it too high, and edges started bubbling, but it still held the light firm.
In my experience white spirit helped me to open the bezels of Thorfire TA13 and Sofirn SF30A flashlights. Like alcohol, its pervasive.
Turpentine should also work, it helped me dissolving a massive bonding layer of glue from a battery pack in the case of a DIY power bank I once built.
Depending on how tight and how much glue a nice bunch of hours for it to work, or maybe a day or two, may be required.
What effect would white spirit have on a driver? Some drivers are glued and a real pain to get out.
JasonWW I doubt white spirit will have any detrimental effect on a driver board. You can also try with gas, after all white spirit is similar to gas but with 0 octane rating. Just don't dump that gas into your car's tank afterwards… :-D
Do you mean that gen 1 is good and gen 2 is bad?
Are all companies that manufacture these lights using the same holders?
I’ve wanted to try your holder for some time already. My employer purchased a 3D printer a week ago and I hope I’ll be able to use it. Anyway, I know that I like the current holder and I don’t yet know if I like yours - and I would surely want to order something that works.
Yes, 1st gen had thicker grips and gripped a lot better. it looks like every light of those types no matter the brand come with identical holders
the stl in the link i posted isn’t mine, it was designed by gchart. mine are for wider bands. they are larger and thicker, i’ll post pics when i get home.
molded plastic is much stronger than printed, (i have not tried polycarbonate, or nylon, or carbon fiber filled filament, they supposed to be stronger, but my printer can’t handle them) i have tested several designs, printed in different positions, from different materials, (petg, abs) , as well as oem. i bend them to the point of braking, that is why i designed mine to be thicker, and larger then oem, Gchart’s design is strong enough to last a long time, if printed on the side, (layer orientation matters a lot, as far as strength) uses original rubber strap. he also designed one for wider strap.
Simply amazing
BTW I wonder when will we see a Type C variant…