Hi. I would like to share the results of modifying Sofirn SP35, which involved replacing the diode.
XHP50.3
SST40
SFT40
Osram
IMO XHP50.3 is a very good choice for this flashlight. The range is slightly shorter than SST40, we gain a longer turbo, and the high mode is stable, at least at an ambient temperature of 25 degrees