Took a peek at the last one, at least for as far as browsing a few russian/spanish transgoogled pages. Buck-boost engine, 2.75-4.35V input range, lads speaking of triple parallel nichias. I guess it's geared for 1S emitter output voltage ranges (actual range?), Tamagotchi commented some sort of negative answer after someone asked about driving UV emitters.
Nice.
I believe you should move forward, step by step or whatever. Share and improve your designs. Once you get some good buck, boost and buck-boost designs freely available everything would go much smoother and with way less complaining. 
Cheers ^:)
P.S.: #1 link fix: [[ GXB20 Driver – Homemade Constant Current Programmable XHP50 Single-Cell Boost Driver! ]]