After reading a review of the iX500 here, I really wanted to see if the background PDF converter would work with my S1300. Thankfully, Fujitsu seems to have finally allowed downloading of the ScanSnap software without jumping through hoops, and the iX500 version of ScanSnap Manager can be found here.
And indeed, after a quick install, and ignoring the prompts to set up wireless on the iX500, it works! Once that’s done, go into settings, and change your profile is scan to “Searchable PDF Converter”. I would hope Fujitsu will release this version (6.0Lxx) for all their scanners, rather than sticking us previous adopters with the 3.2Lxx series, but who knows. Maybe I haven’t found the actual issue yet. Also makes me wonder what happened to version 4 and 5, but I don’t overly care. It works, and that’s enough for me! Good luck, and comment if you do or don’t get it to work.