An AR coated lens would be a good start. There’s nothing like looking at the led on a modded Courui through a “milky white” lens

CREE XHP35 HI NW LED
Boost driver (1.5-1.8A on the LED)
Copper pill. Or to make a head absolutely without a pill. So that the star lay right on the thick partition.
DTP Base (star)

The reflector should be of such a form that the base does not short-circuit the contacts on the star.
The original was not very well focused. The spacer washer had to be sewn as much as possible.

http://forum.fonarevka.ru/showpost.php?p=875211&postcount=250

Square thread-anodized, option to longer battery body+3S battery carrier. Thicker Aluminium pill with 32mm copper DTP. Water proof side switch button. Driver to add brass ring for durable contact wear and tear. Driver chamber change to thinner wall but with fins to cool down faster.

• Threaded driver retainer, or driver retained by screws.

• Revised reflector base to prevent shorting of LED wires on underside.

• Better quality threading at battery tube/head joint.

• Better quality machine work inside battery tube (sharp burrs cutting battery wrap).

Must have:
1. Real current regulated driver with good modes spacing (i.e. Moonlight, Low, Mid, High) without the visible PWM pattern;
2. 32mm copper DTP board for XHP-35 HI / XP-L HI emitter;
3. Make the LED pill thicker to allow the LED sits further into the reflector;
4. Modify the reflector base to avoid shorting the electrical contacts (as already mentioned above).
5. Convert the batter tube into 3S batteries configuration (instead of the current 3P), so that it can easily run with XHP-35 HI, or run with an XP-L HI with a buck driver.