Should work with a triple xpg if wired parallel. The driver appears to be a buck or just direct drive when the supply voltage drops below the vf of the led at 5amps. Notice what it says “Constant current output when the voltage is higher than the LED VF value”. Wouldn’t be much different if you just used direct drive, like the east 92 driver with a single 4.2v cell.
If you used a XM-L2 on a copper sink pad at 5 amps the vf would be around 3.75v. Emitter Test Results pt4: XML2, XP-E2, XP-G2, and Nichia219! (along with sinkpad tests)
If you used a Panasonic 3400mah or a sanyo 2600mah the voltage would sag below the vf of the led at 5 amps in under a minute. Then it would be basically direct drive after that point. Battery test-review 18650 comparator
A 18650 IMR wouldn’t even be able to sustain 5 amps for very long. A XM-l on copper will stay in regulation longer, maybe around 10 minutes at 5 amps, just a guess.