Yes, I would be interested in that too.
From the emitter list I am familiar with the 365nm leds, so I immediately bough a D4v2 with 8 5W uv leds 
But I would like to get 2 more D4v2 lights with regular high CRI leds like Nichia 219, and not sure which one to choose because there are so many new leds.
The new D4k, how larger is it compared to D4v2?
I found the following reddit threads helpful for helping me pick, it’s not a comprehensive list but it’s most of them:
Niceee
So best option looks like it is a Dual channel Emisar D4v2 with W1 + 519 4500K
There is no best as such, it’s always a compromise, that’s why all the other options exist (and are frequently ordered) in the first place.
True. But if you want both good throw as a search light, and nice flood for when you want to light up a big area closely, I think those are the best options.
Question regarding dual channels: does ramping work the same with dual channel lights? I mean, can I still have low to high lumen ramp for just 1 channel that I choose?
Will the KR4 be upgraded to 21700?
Yes, brightness ramp works just as expected (1H), the channel mix is set with 3H (it replaces momentary turbo).
This would be awesome… A compact sub-50g triple to beat FW3A / FW3X. 14500 lights are intresting also, but IMO it trades a lot of runtime/heat management for size.
Am I wrong when I say lh351d is a better flooder than 519a? I like the tint better with 519a but I’ve heard it’s not as wide/flood as the lh351d.
519A is still pretty floody, and has a better tint and higher CRI than the LH351D, but with less output. In lights with TIR optics, there will be a very wide spill beam for all emitters. However floodier emitters will have a brighter spill beam and less bright hotspot.
Hank, do you offer D4K as mule with 16x E17A 1800K or E21A 2000K? If so, would a boost driver make sense, too? Hoping for a positive reply.
It's right there in the "DESCRIPTION"
The boost driver upgrade is available for the SST-20, Osram W1/W2, Nichia 219B R9080, as well as 519A version, each LED receives 2A current. The driver is not compatible with Nichia E21A, Nichia E17A, and mule versions of the flashlight.
Also hoping for a xhp70.3 D4K, mule or shallow op…
I’m afraid that you have to make custom D4K by your own, buddy.
Awesome. Thanks!
Hank, can you post a picture of a D4K next to a D4V2?
I just saw on Reddit D4K next to a D4V2. I like it a lot but the only thing i didn’t like is the clip.
I have a feeling it won’t fit easy in in the pocket…
here it is:
https://www.reddit.com/r/Hanklights/comments/xknihj/i_got_my_new_d4k_today_im_loving_it_also_some/?utm_source=share&utm_medium=web2x&context=3
How come they both have same thickness ? Tube is thinner on D4k?