Hi Akram,
i would say dont eat them if you can see latex like you mention as this seemed to effect bad for you, i just dont see latex when i pick my figs i suppose because there very ripe at the time of picking.
I do understand your feelings of seeing one on tree near ripe late in season but just not there yet and the temptaion to eat it. ; )
Perhaps if brave enough even if you see the latex after picking fig cut some of the end part off fig where it met tree and then run under water either whole of cut in half.
Im sorry but i have no better definitive answer only something for you to try.