I have already modified a couple of flashlights by replacing the XML2 with a 3-volt XHP50.2, without making any other changes; the drivers provided 2700mAh; the lumens in addition to an XML, there are, and the beam of light is more flood (at least with the parabolas of default with a diameter of about 27mm); I think the performance of an XHP50.2 is higher, with the same Amp, at 3 volts.
Overall I am satisfied, in fact, slowly, I will bring other flashlights to the standard one.
Regarding the P60, yes, the problem is the greater heat, it is a must to fill the space between the P60 and the head with metal plates (I use aluminum, beer cans) but certainly copper would be better