Thanks for the review, loving the aux lights!
I fear, you won’t have fun soldering pogo pins aligned with your design, lexel, something like this with a notch for automatic alignment might be better. Was still difficult to solder though, especially with iron, I was successful with hot air finally. But hot air might cause problems with a 2-sided design.
A SIM card connector (mini, micro, nano) could work, but is OTT. And no room.
Pogo pins onto vias or pads is the obvious way forward, at the moment.
This has to come, since MCUs will have no external pins to clip on to, even if there is keep-out area for a clip.
I’m hoping Hank might offer a flashing kit too, but I don’t know if that will happen. For now, I could stand to get some pogo pins (or really any pins) to put into my ribbon cable, since I haven’t had a chance to try out the flashing pads yet.
such a cool light, hope it won’t be too pricey. thanks for the first look
Really hope this will be available in the new white surface as well as a floody optic option!
And red or amber aux LEDs. We can always dream can’t we? 
The pink surface-mount LEDs are nice. I built a clock with those… one LED per pixel.
I’d love to see a mixed LED board with two resistors to adjust the relative brightness of two channels. They’d both still be on at the same time, like the current design, but the colors could be a lot more interesting. Like doing half-and-half with royal blue and photo red emitters, to make a really vivid purple.
But TBH, I don’t care all that much about the aux LEDs. I’d much rather have the option to get a primary MCPCB with two LH351D 4000K 90CRI and two LH351D 5000K 90CRI emitters. I think that would be just about ideal, both on the D4S and the original D4. This sort of mixing doesn’t work as well on a triple, but a quad is a perfect host for it.
Purple anno and purple LED’s (blue/red)!
Or 2700K/3000K and 5000K. The problem with that is there is no optic for that. Mule only?
Er, it could do 3000K + 5000K if you wanted it to be a 4000K light. There’s no problem with the optic which would interfere with that.
I want it closer to 4500K though, and neither the 219c nor the LH351D comes in that tint. So I may try to mix 4000K and 5000K emitters. Plus, it’ll probably look a bit better than a native 4500K emitter would anyway, because tint mixing is cool that way.
Or I could go even wider like I did on my wide-spectrum BST, with four different tints ranging from 3000K to 6500K, but that’s trickier to get right, looks weirder up-close, and makes rainbow shadows. The result on mine is pretty fantastic though, and it really makes colors look vivid.
Ah, I just re-read your original comment. I thought you said 4 of each (kind of like the BLF LT1).
Has anyone tried mixing the 4000 and 5000 K LH351D with the clear Carclo quad? Does it blend well or are the corners visibly different and you should swap to a frosted one? And does the angled quad board help compared to the old version?
Do we think this will support 26350 with a short tube?
Please hurry!!! I can hardly wait to spend money I don’t have on another light I don’t need!!! Thanks to all involved. I really want this one!
The board I dersigned for the D4 can technically run each LED on a different color does not change brightness down to 2.8V
but I guess there is not much demand in a board for the D4S that can do that
I’d certainly like one 
I will make one! But no matter the demand, the design is already a joy to look at
I honestly never cared about any “aux” light coming out of any flashlight other then the main beam… Then came GITD orings and tape under the optic, lighted switch, tritium, and now this!
Why do i care now? :person_facepalming:
Note that if those aux leds where located under the optic, close to the main leds, they may allow for tint tuning somehow?
My 5D+3D+3D+2B light is now using a MCPCB with rotated pads under a clear optic, and it looks pretty decent. The center blends well, and instead of four blatant corona petals it has a bunch of much less obvious petals. The frosted optic is of course much smoother, but the clear optic works okay and throws better.