Well, this light was not designed for modding. The designers made it for the drivers they had. I guess initially it was sold with different color XP-E LEDs so there is not much power allowed.
The 1405 variant has two cells so you can run a 6 V LED with a 17 mm FET driver if you want power (XHP70 Retina Burner). Cooling is a problem because the pill is inside the tube inside the zoom head.
There will be a two new 17 mm boost drivers soon (loneoceans and his GXB17 have resurfaced and Schoki/Lexel have a unnamed driver in the making).
If you want to use any 20 mm driver check out this trick for testing.
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The costs for making a copper KKW design style pill would be about $20 with a minimum order of 10 pieces. I asked around some time ago but never got enough buyers together. With an improved internal shape of the pill the thermal conductivity of aluminium may be good enough and the pill would be cheaper.