Here’s a cheaper option with a bit more power handling UV led.
driver - Shop Cheap driver from China driver Suppliers at Convoy flashlight Store on Aliexpress.com -?
2450ma might have been a little too much current for the Nichia. Seems like I’m usig a 4-amc7135 driver in my S2+ and it does get a little warm.
Djozz gave us some pretty useful test data for output using a LG UV led. LG 365nm UV led tested (LEUVA33W70RL00, from Simon)
Use a copper mcpcb and looks like from Djozz’s graph staying around 2100ma (6-amc7135 driver) might be the sweet spot, 2450ma (7-amc7135 driver) if you wanna push it.