I didn’t find anything specific either. A page 30 in the datasheet there’s a graph for voltage in vs current out at 12v out. It looks like with a voltage out close to the same as the voltage in gives about 5 amps pulsed, 4.2 amps continous. In a flashlight the current out would probably depend on the led vf at that current compared with the cell voltage of say 3.8v. As long as the cell voltage is above the led vf at 5 amps it should buck at 5 amps pulsed, about 4.2 continous from what it looks like to me. I dont find any graph or info that relates to that besides the one on page 30 with 12v output.
3119fb.pdf
I found one more reference at page 28 in the bottom graph. For Vout it says 3.3v at 5 amps, >4v.
Its probably going to be led vf specific vs cell voltage.