My comments on the design:
1. emitter choice
Based on this source:
https://forum.openrov.com/t/what-is-the-best-light-color/3453/5
An ideal diving flashlight:
- has very high CRI (every well represented part of the spectrum is important for collecting visual information, and under water, this is even more important)
- for close search (up to maximum 10 meters): has a rather warm looking CCT (3500-4000K), and rich in the red part of the spectrum
- for spotlight (far) search (up to 100m): has a neutral to cool looking CCT (5500-6000K), and if possible, doesn’t have noticeable cyan weakness (dip) in the spectrum
So I think, unspecified CRI + 7000K is not the best choice.
Based on the design, this light is intended to be a medium range searchlight, for which I recommend 5000K CCT Samsung LH351D LED. It is cheaper and better at the same time. Also do not bother with Cree XP-L2/XP-G3 LEDs, as they have horrible looking beam.
Also, as I see, this is not a really high power flashlight, so instead of LH351D, choose LH351C for a bit of additional throw. LH351C is stable at 9W (~2.7A), LH351D can do even 16W (~4.5A).
2. battery
Not mentioned in the specification, but I guess, this is a 18650 flashlight.
3. output levels
If only 2 constant output modes are considered, the lower choice could be at 40% instead of 59%.
Mode cycle could be better if this would be the order: OFF > MID > HIGH > SOS.
If the rotational switch could be manufactured to include one more position, I would add a LOW mode at 12% as well.