Kwik-Flex screws into light gage framing - tension pullout

The published Hilti technical data on the Kwik-Flex screws list an allowable increase for both 1/4-14 and 1/4-20 screws of 1.44 when installed in steel with an Fu=65ksi or greater (highlighted on attached). The ESR 3332 report (Dril-Flex and Kwik-Flex) allows the same 1.44 increase for 1/4-14 screws into steel with an Fu = 65ksi min., but limits the increase to 1.15 increase for 1/4-20 screws into steel with an Fu = 52ksi. min. Has Hilti conducted testing to support the 1.44 increase when installed in steel with an Fu = 65ksi min.? Or there some other explanation for this discrepancy?