Beam shots in post #1 and more tear down photos are in the OP.
beasty looking light. I would remove the handle if i got one, and replace it with a paracord lanyard (something like the BTU Shocker has) using four 4500mah 26650 cells this light should have an amazing run time.
Ahh, ok. That explains it -- multi cells makes a big difference with this light, both with the stock driver and when I wired it to true DD (no driver effectively). Also the Mnke cells I have are poor performing compared to KK's, and any other 26650 IMR cell I have. I know my Mnke's though are old, and the older ones were worse that what they sell now.
From my testing/experience, the EFEST 4200's are (were) the best cells on the planet, but are now dethroned by the Basen 26650 4500 IMR cells -- a new king, maybe in my eyes only 
. They test over 4500 mAh on my OPUS. Jon at LiionWholesalers tested these for resistance and performed slightly better than the EFEST 4200's. My testing confirmed that, in real DD FET lights.
I re-measured the cavity above the driver and it's between 9.4 and 9.5 mm - plenty of room for a piggyback driver. You have to include the loose ring spacer that the driver sits on.
I bought two Basen cells off of eBay here - they are legit. I got 3 more shipped today from here: liionwholesale.com-basen-4500mah-26650
These cells he just listed up there today - great price, decent prices on shipping. Sorry all, but he's my new favorite source for cells - quick, cheap, excellent service, seems to know his stuff. Can't wait to try 4 of these in the BOSS 1 though - couple more days.
I added your info in the OP. People should read all they can when thinking about a light. You have great success with it and I just don’t like it, but that’s just personal opinion, so people should try to be as informed as they can. I used new MNKE cells for testing. I have had good luck with them, but I don’t buy a lot of cells. In fact I had to buy these, because I sold what I had. Thanks for the informative posts. For me, it’s just going to be an XHP70 floody light, if I do anything at all with it.
Ah, I missed that! Although to tell you the truth, at this point I’m quite foggy on ‘good’ kcd numbers @ 10m. Do you have any measurements / links handy for comparison? Whatever you think is appropriate. TIA
I glanced around your posts in that thread, but I couldn’t figure out whether those numbers were in true DD (entire stock driver bypassed besides vias) or with an FET driver?
I still don’t think much of the looks, especially the handle and where the handle mounts (with those sloppy countersunk Philips heads). I think for now I’d better consider what I can get out of that Courui D01 I bought and never modded. 
For 10m throw measurements, here's the deal. It's been generally proven any throw measurements under 10m is biased to being low. I've proven this to myself recently, but rdrfronty and manxbuggy1 have done the most thorough research on this I've seen anywhere, and they have proven it. Their results showed 10-15 meters is pretty ideal. Anything over 15m doesn't make any difference - they went out to 100's of meters and saw consistent results with what they measured at 15.
If I had my preference I'd use 15m (my backyard is limited), but I believe they found not much difference between 10-15m. They, and others I recall, pretty much agree the minimum distance that should be used for reliable results is 10m, and again, 15m is more ideal. I don't recall where this was all stated/tested but you might find it in these threads below - I keep these bookmarked because they are still some of the best ever posted on BLF for throw measurements and beamshots to this day:
https://budgetlightforum.com/t/-/18214
https://budgetlightforum.com/t/-/18774
https://budgetlightforum.com/t/-/22397
https://budgetlightforum.com/t/-/25465
Best definitions/equations for throw, Dr. Jones: https://budgetlightforum.com/t/-/3879
- For my BOSS1, the mod is direct wired - no driver electronics, no FET.
- yes agree: the handle is kludgy but actually works quite well. This light really needs a handle and I found it be sturdy, comfortable ,and totally ugly. Another words, it's not as bad as it looks and it's really, really needed - my hands just ain't that big to comfortably grip this monster. It's the only handled light I kept the handle on.
Good insight, I’ll check those threads. Thanks!
this flashlight should use an xp-l HI led for further performances as thrower
Well dedomed LED’s throw better than any XPL-HI, and I don’t see this light worth much stock.
For stock, though, maybe you are right. The extra cost of the XPL-HI for the manufacturer wouldn’t amount to much of an increase. I don’t see this light selling much from GearBest, now that they raised the price. The group buy doesn’t seem to be happening as well.
So this light is there because of the huge reflector that promises extreme throw (if you mod it well), and, with four 26650’s powering just one XM-L2, it will have a massive runtime.
OL was complaining about limited room for a heatsink, but because it will never have more than one emitter (even if that is a XHP70) the light does not need a huge heatsink, a 2mm copper plate will provide all the heat path to that massive aluminium body that you ever wish for.
That empty driver with those 2 tiny FETS is probably outperformed (resistance-wise) by the cheap SRK clone that I bought recently. Why does it need 5 big diodes???
Yes, I totally agree - of course with the skills of O-L, Dale, and lots of others, you can do almost anything with this monster but the unique value is the the huge reflector and hefty power in a 4.2V max setup (parallel). The diodes are on a per cell contact basis - each batt+ contact has it’s own diode for reverse protection.
Ah, thanks, now they make sense to me 
I have a question - is the head glued to the body? I want to replace the original emitter, but it is kinda stuck there, I cant unscrew it. Thanks!
No, I didn’t find any glue on mine. From the pics in the OP, O-L’s threads look clean as a whistle. Can’t recall struggling with it, but I’ll use my tacky blue work gloves for connections that are tight - grip makes a huge difference.
With mine, the head was on very tight, but it did not have glue. I had to use two of the adjustable rubber strap clamps to get the head apart.
The reflector is huge!! Is this reflector diameter about the same as the one in Olight SR90?
Who has modded this light into an ultimate thrower? Wonder if it modded with overdriven dedomed XP-G2 or XP-L HI could produce anywhere near 800kcd?
Post #268 here: https://budgetlightforum.com/t/-/36643/261, or here: https://budgetlightforum.com/t/-/36643, whatever works.
Got 685 kcd steady with a XP-L dedomed.
could you post some beamshots?
Ahhh, not sure when I could get to that. Nothing close for open fields or long shots.
Ahh great! So this thing can really throw a long way!