“If you make a claim that one thing will lead to another, and someone says that’s a slippery slope fallacy, what are the chances they will accept that it isn’t a fallacy if you then elaborate on your reasoning for why one thing will lead to another? Basically zero, because what they meant wasn’t to criticize your failure to provide reasoning, it was to dismiss your claim on the basis of its shape and to…”

I don’t disagree with this at all. That’s why I avoid arguing with people on the internet.