any tube light is going to get hot driving an emitter at 3a, be it xm-l xm-l2 or xp-g2, I have a 26650 tube with pretty good mass and that gets hot after 15 to 20 minutes on high.
As matt says, to have a cool running light, you either have to cut back on the drive current or……just use the modes, treat full current as a turbo with medium and low as your regularly used modes.
My recommendation would be to look at the convoy range of hosts, illumination supply do carry assembled lights but I’m not sure about the hosts.
If your looking at solarforce lights and do want to do a build, this is a good one too
this is one of my work edc’s and it really does handle 3a very well given the outside dimensions, I’d certainly prefer this over a p60 host as I really just dont like them.