Hank told me lighted switch on aluminum was a no go when I asked him last week. Really wish he would do it. Didnāt stop me from ordering another D4v2 with my K1 thoughā¦
Short answer - Yes.
Not positive on that.
I donāt have a full-copper D4V2, but I do have full-copper for a number of other lights.
Copper conducts heat so well the body tube of the light where your hand sits can get burning hot far faster than an aluminum tube.
The result is the electronics might be protectedā¦ but you may need gloves (or an oven mitt) to actually hold the light.
I noticed my fw3 copper got hot very quickly. My brass d4v2 does too, but with different emitters in my 3 lights of comparison itās difficult to tell why or how much faster.
Ya my KR4 gets pretty hot cause I use it as my desk light. I try to keep the brightness at a level that is sufficient but doesnāt make the light get warm. Sometimes I neglect to do that and it gets hot. Not sure if that affects the life of the light but if so it just gives me a good excuse to buy another (:
Iād love a D4SV2 in 2000K.
I would love green anodization and clear anodization options for Emisar D4V2.
Someone on Reddit modded a D4V2 and silver color looks great. It would look even better with an optional backlit switch. 
EDIT: I just realized that Hank might not be able to access the images that we post. Some websites are not accessible from China, including imgur(.)com. Hank might not even be aware that you posted an image, because when you include an image in your post, and the website is not accessible, a browser might not give any indication that your post contained an image.
Iām really excited to see what happens with the d4sV2ā¦ Will Hank rerelease all the colors again? Will he redesign it into a V3? Will it become discontinued to make way for a similar but upgraded version of itself? Will any of these three options I mentioned be available in cuā¦?
These are things that keep me up at nightā¦
Put down the flash light and slowly back away. Unscrew one tail cap per night 1/4 turn and ween yourself off. We will get you through this.
These two beauties arrived yesterday (after only a few days of shipping)...
Please excuse the miserable image quality - I took some snapshots with my crappy smartphone camera.
Noctigon KR4 using 4x SST20-DR 660nm underneath a clear Carclo 10622 optic. At my request Hank installed a 7.5A constant current driver (default is 5A if I recall correctly). I was really impressed, even shocked a bit how bright this beast gets on turbo. Somehow, being blinded by deep red light felt totally different to my eyes than when using white light against a white wall. Anyway, 10 seconds later the head's temperature has climbed significantly, so I will use turbo wisely and for short bursts only. Maybe it's not a bad idea to manually set an ultralow threshold in AndĆŗril's thermal config...just to be safe in case. :-D
Noctigon KR4 using 4x E21A 2.000K underneath a frosted Carclo 10623 optic and the 5A constant current driver. The light beam is real eye candy, actually representing the quintessence of candle light. The first thing I thought of was testing the candle mode in AndĆŗril - amazing is the right word to say. In comparison to the SST20-DR version this KR4 took an eternity to heat up that much. Maybe I should tweak thermal config a bit to see what presets work best. I removed the clips on both lights and feel very happy with the alternative lanyard rings Hank supplies with these lights. The matte black anodizing is just perfect, same as the overall quality of both lights.
Hats off to Hank and ToyKeeper for bringing us more and more seductive flashlights. :-)
I highly recommend the 10622 clear optic for E21A 2000K and E21A 2200K. Throw is a lot better, and tint shift is a non-issue.
I did not try it with E21A 2700K yet. E21A 3500K does have noticeable tint shift with 10622 clear optic.
Iāve got a brass E21A 2200k and I canāt get the frosted optic out. Every other D4V2 is easy with a piece of tape but I canāt get this one outā¦
I had to use 3M tape. I pressed it on the optic for 20-30 seconds and then pulled up and the optic popped right out. Pull up on both sides of the tape so the force goes straight up. I think the thermal grease acted like glue on the optic legs.
suction cap works too
Donāt cringe, but I gently use the back corner of the blade (last mm near finger choil) on my pocket knife, place it under the optic near the tab and it pops out every time. Gently though, so not to scratch the front of the optic. Good luck.
OKā¦okā¦ I will tryā¦ slowly puts kr4 down placematā¦
Thank you for sharing these two intriguing versions of of of the best lights I own! Honestly I have been wanting a e21 version of this for a bit now, but Iām
HOPEFULLY, CALMLY, holding out EAGERLY anticipating a
ALL brass or ALL copper version of the KR4ā¦
Hankā¦. Hank ?? Hank!! 
I inserted a firm thin object into the gap between the head and the optic and used it to lift the optic up.
The tape didnāt work for me but I was able to get a small razor blade under the edge of the optic and pry it up finally. Two of the legs were being held in with thermal paste.
I found that a nice piece of moderately thick plastic (I used a bit of an SD card package) works nicely. Too soft to scratch the optic or frame, but enough to pry it out.
Also we all got too excited about the wonderful e21a 2000k and 2700k LEDs, they appear to be out of sock at the moment.
I ended up also changing my E21A 2700K R9080 flashlight to clear 10622 optic. It looks great.
I didnāt think I could like my warm white E21A flashlights more than I already did (they were my favorite), but clear 10622 optic made them even better. I love the increased throw and sparkly aux lights. I highly recommend this mod to everyone.
Clear 10622 optic is a great choice for these leds:
E21A 2000K R9050
E21A 2200K R9050
E21A 2700K R9080
I prefer frosted 10623 optic with this led:
E21A 3500K R9080
My standard for deciding whether clear 10622 optic is a good choice is the following: does the beam look good and even on a white wall.