Coax cable loss is of course very important, but we should not forget that the Model 404-UL's coax is only 12m (40 ft.) long.
Keep in mind that the Model 404-UL was designed to be an ultra lightweight antenna for use with fiberglass poles. We must rule out the use of RG-213 immediately.
RG-58 could have been used but the improvement in coax loss would have been between 0.3 and 0.6 dB, depending on the band. But then we would have had to drop the antenna's feedpoint one or two meters on the fiberglass pole to prevent breakage.