XHP-70 emitters make more fuss about being pushed hard. 
Times 12. Still, it’s not all about the heat, power consumption is problematic for the limited power supply. The number of places that require compromise is the real issue.
Even with 9V MTG2 emitters, 4 of them make a lot of heat. I have a TrustFire TR J-20 that uses 3 32650’s to power 4 9V MT-G2’s in parallel and again, in spite of a ludicrous amount of additional heat sink the light does get hot pretty fast. And it “only” makes around 14,000 lumens. This light is monstrous, with very deep fins and a LOT of them. Insufficient. Big power is just difficult to do on battery packs that we can hand hold. We need to use the flashlight to house the cooling system and a belt mounted battery pack to supply the power, this would remove the pack from the heat of the operating light and allow for much higher efficiency. Keeping the cells so close to the heat source is just folly, when maximum lumens is the game.
My big light, or the triple 70.2, is my 5th scratch built light… hence DBC-05. I started this literally the day before I blew out 2 discs in my neck, finished it (as a different plan) after neck surgery. It was satisfying coming back and achieving the results I saw. I don’t take pics while on the lathe, sorry. I’m not a machinist, I’m a photographer… I do NOT want my equipment out in the shop and I DO want to keep all my fingers…