Never mind what I’ve said. If the driver in the flashlight “direct drives” in high mode (see Is this safe? ), a lower Vf LED (XR-E drops 3.7V@1A) would probably get fried with too much current. So a new driver would be needed, and this flashlight has a 20 mm PCB in its hole when most drivers are 17mm in diameter… So s**t finding a proper driver… LOL
Cheers