Meh I don't see the point of a 14500 light that is not dual fuel. If you want a light smaller than 18650, try 18350 or 16340 and anyway keep it small by not including a usb charger and maybe not a side switch. These manufacturers are too obsessed with high lumens because the unwashed buyers want that too. We (sniff) sophisticates have gotten past that by now, lol.
I'd change a few things about the Sofirn SP10 Pro if it were up to me, but it is basically the right idea if you want an AA-format light. The Manker E03 is another option, but I always want Anduril if I can get it.
To each their own, but I see no practical use for AA. In fact, I see AA-compatibility as a relic of the past, just like insisting that gasoline needs lead or PC's need floppy drives. It makes some people feel better, so it's a nice marketing tool, but I've moved past 2005. The only thing I have in my house that can even take AA's is my Rider RX.
For me, it's not about the lumens. At least not with 14500 lights. No 14500 can match my 18650 lights there. That's not what smol-lights are for. But 16340 lacks the runtime of a 14500, and when I carry a 14500 instead of an 18650, it's usually more a matter of girth than length so 18350 holds no appeal for me.
To head off another argument I've heard, my experience is that any alleged runtime advantage AA has over 14500 is only because of lower lumens. A light that can run at the same lumens regardless of battery, whether due to step spacing or ramping, will last longer on a good Li-ion. Those Vapcell F12's will outlast two white Eneloops, so 14500 beats NiMH. As for alkaleaks, I've been in exactly the sort of situations that many AA-lovers think dual-fuel is required for and been left in the dark, sometimes for days, as a result. Plentiful? Not in a natural disaster. If you're the type that only keeps a couple dozen around, you'll run out by the fourth day. And when I tried to use the infinite supply of AA's at work to get out of charging a 14500, I was so disappointed by having to swap batteries so much more often than I needed to charge that "all the AA's you can eat" was not worth it. That was the final nail in AA's coffin for me.
Experience guides opinion, and my experience has been such that pretty much every pro-AA/pro-dual-fuel argument I've heard has been debunked. Or at least deprecated since 14500's broke the 900-mAh mark. I do not thinking a larger, less efficient, more complicated and expensive light is worth a feature I will not use. If I wanted a(nother) oversized, expensive light that could take 14500's, I'd get a fourth D2.
I agree with ditching the USB-C port, but there's enough folks that find external charging to be blasphemous and immoral that I can see why they included it. Besides, the optics/reflector requirements of a thrower give it a bit more "wasted" space than a floodier light like the TS10, so it's less of a hassle.
16340 and 14500 should be about the same in terms of volume, weight, and capacity. I do understand that the 16340's extra thickness isn't always a good thing.
14500's hold a bit more energy than white Eneloops, and weigh considerably less, so I don't claim Eneloops are superior, but only that they are sometimes more convenient (they run almost any AA-powered device). 14500's used to actually scare me because of the possibility of some idiot (most likely me, but maybe someone else around the house) putting a 14500 into an AA powered device by mistake.
I'm not that keen on the AA format for flashlights in general these days. If I want something slender I probably want an AAA light. Their main drawback is I don't know of any with Anduril, while for AA there is the SP10 Pro (or the DW4 which is 14500-only). The main attraction of the AA format for me is generic batteries or dual fuel. The ability to use L91 lithium AA's is also nice for some purposes, since they are very light (around 15g), have super long shelf life (decades) and work in very hot or cold weather unlike most rechargeables. CR123A cells are also like that, so if a 16340 light can also use CR123A (i.e. it has a boost converter), that is a good feature.
I'm using an AA powered computer keyboard right now, normally run with Eneloops, but they went flat and I didn't have my charger nearby, so I put in alkaleaks and kept typing, very handy.
For lights, as mentioned, high lumens in small lights are basically a gimmick, useful for quick bursts at most. At lower lumens, runtime is generally not an issue once more than a couple hours are available. You can always bring a spare cell.
I will probably get a Nitecore HA11 (very lightweight 1AA powered headlamp) sometime, partly because there is no decent 1AAA light in the same style.
I agree with people who think using an external charger ala Hanklights is a pain. 3.6 volt 16340's with built in USB charging exist, though (example). I don't know if there are 3.6 volt 14500's like that, only those silly 1.5 volt ones with built in voltage stepdown.