The concept of A4S is great.

I think multi-LED is the future of flashlights, BUT along with a powerful boost driver. The era of DIY FET driven lights being more powerful than productions lights with boost driver is coming to an end. One of my favorite lights is the Sofirn C8F, and the only way to improve it is with a boost driver so it gets flat regulation.

Linear drivers are appealing for some people but for me it is dumb to burn excess power, might as well just drive the LED harder.