This is a “driver” with only current limiters controlled by the master driver , you can see the wiring here:
YuvalS's Hand Made Class, 7th Annual BLF/OL contest entry topic - #87 by YuvalS
Why? what advantage it have over loose cells? Make a battery box for loose cells and never open it if you don’t want but you always will have the option to take or give a cell in case of emergency
Also remember that charging 3*21700 in parallel wit take ages even with 2A charger. Usually in expeditions not a lot of sockets are available and you want to be able to charge it fast in external 4 bay charger…
If you have a CNC you may want to have a look at this project
And also in this blog that build some lights using the above housing
Both in French but google translate can help
For the speech recognition light I have used 3 deg optics with XM-L2 not sure you really need more. Keeping the current up to 3A make everything compact and relatively efficient. You can de-dome the xml or use other 3A LED with better throw.
Using 2 different drivers has an advantage or redundancy, it is kind of 2 different lights in a single housing but I don’t like this type of UI of 2 switches for 2 LEDs.
It means that you are probably Croatian 
It is FW related but you can do it, my FW is on GitHub