That is great news! I think with the 21700 form factor, people will be buying the S2+ 21700 to mod with quad emitters and carclo quad optics like how everyone was modding the S2+ 18650 with triple emitters so I think we need at least 10A max mode. But that might be too much for the stock single emitter.
Normally the lights come with pocket clip
About the UI, you can configure the modes you want according to the this diagram: http://i.imgur.com/jvx04IR.jpg
So, you can put it starting from moonlight, if memory is disabled! If memory is enabled (last mode memory), you can leave it in Moonlight before turning the light OFF and then it will start in Moonlight.
Taking into account the configuration of this flashlight (4*7135, and Nichia), I would recommend Panasonic NCR18650B (it is not a high drain battery, and has plenty capacity for longer runtimes).
Why triple when the original S2+ can already accomodate triples? The S2+ 21700 should be sized to accommodate a Carclo 24mm diameter quad optic. Quad will provide a little extra output and efficiency over triple.
The NCR18650GA/LG MJ1/Samsung 35E are at most about $1 expensive more than a NCR18650B (if not the same price) and surpass the later in both capacity and discharge rate. IMHO unless price is a prime concern (and you are buying many cells to offset the shipping costs) there is little reason to buy a NCR18650B nowadays.
Nice I don’t know or own the ones you mentioned, but I guess they must be taken into account then! I remember seeing the graphic for the Samsung 35E and indeed they are good! Thanks for “correcting” me on this
High CRI emitter options, very nice to see Simon. Still, for driver I would prefer something regulated, PWM free. Stock configurations with LD-25 could be a nice idea, although I understand it increases cost a little bit. Or maybe not? It's a supply and demand thing, doesn't it?