I have done several Olight LED swaps. Not easy but worth it afterwords. I have only had the driver out of a couple, not worth the effort and time. That is a reflector model, I would try to stay with the same size die for the best results. Although I did install a 219B in mine and love it. If you do one with a TIR, you really must stay with the same size die. The beam gets really ugly artifact wise if you go to a smaller die.
How hard is it to get the bezel off? The S15 has that inset bezel with about 6 notches. I’ve wondered if there’s a special tool for this or if something common can be used to take it off without damaging the anodizing.
Personally, I don’t think there’s much value in replacing the emitter, but I’m thinking of installing a minus green filter under the glass.