Maybe I make it into a self-answered question, maybe not, in any case, if anybody else ever has the desire to produce non-crashing (invisibly) PDFs by GeneratedDocument under Mac, here is my simple workaround: `nonCrashingGenerateDocument =
If[$OperatingSystem === "Windows" ,
GenerateDocument[#1, #2,
{"ProgressIndicator" -> False, "HeadlessMode" -> True}
]&
,
(GenerateDocument[#1, #2, {"ProgressIndicator" -> False, "HeadlessMode" -> True}
] /.
(s_String /; StringMatchQ[s, "* *fl*"] && StringLength[s] < 200) :>