I’m sorry, but what I said was “It was never proved that it was the Syrian g0vt that used chemical weapons the first time.”
So your question: “Which of the roughly 15 factions is using them? Where is their proof?”
doesn’t make any sense to me.
I was supporting what you said, badly, apparently. The last time there ended up being proof that they were used. Trying to figure out which faction used them was a different matter.