Hello!
Yes we’re still trying to work out the best way to power the star LED. At the moment a variable power supply with constant current mode is our recommended solution.
There’s a few tips in this thread: Delta v.1 Build Questions
For example for the blue LED at 3.3V, I set the current at around 0.1A for fluorescence imaging. It still will get hot, but I find a heat sink (the ones for Raspberry Pi fit nicely) does improve matters, and not leaving it on for long periods.