The topic did not die, but went in a different direction: in the discussion of other lamps …
I remember I set out to try and upgrade my D4V2, but I was literally missing a couple of mm. in diameter and 5 mm in length … There was a hope to bore the tube under the SANYO NCR2070C, but it made little sense, besides, the fasteners in the lid under the lace prevented from doing this.
I think you can make D4V2.21700 just by slightly lengthening the tube and increasing the diameter of the threads (by 2mm). The lanterns will be almost indistinguishable …
But it looks like Henku Emisar is no longer interested, he creates some kind of bells, and changes metals on old models … 
Proton Master + Lux-Perpetua
Thank you for your answers.
Based on your answers, I will probably go for SST-20, more lumens, less heat.
Nice! I have a D4SV2 with the Neutral White - SST20 4000K 95CRI
and is indeed powerful!
I wonder if you could get 2000K E21A on CH2? That might be a sweet combo
I never had deep red. Maybe, I will go for this option.
Is it possible that both channels are active at the same time?
Is it worth buying XP-L HI V3 for 20 $ more?
Thanks
I love deep red. I have it on CH2 for two of my 9.3’s. You can only activate CH1 or CH2, not both… To the best of my knowledge
I have two. Excellent but heat up very quickly.
I received my Noctigon K9.3 : E21 2000K + SST Deep Red 
This flashlight is smaller than I thought; the finish is impeccable as always with Hank
It is much more floody than I thought on channel 1.
Deep red is very intense.
Did you know a diffuser that would fit this flashlight ?
I love that light. I use it all the time indoors…. 
I’m sure someone can advise on a diffuser
I sure would. I love the side switch and the form factors.