In other words, the Nazi ban is one case where the dialog went like this:
"Come on, this is pointless, they can just use other symbols and dogwhistles. You'll fall into an escalating spiral of swatting down new Nazi symbols, negatively affecting pretty much everyone but Nazis."
"Yeah but look, we won't fall into an escalating spiral of free speech restrictions. Because they won't change their symbols, ever."
And they were right. I don't entirely understand why, but clearly they were right. My standing theory is that Nazis are either really dumb or in some sort of symbiotic relation with the constitutional protection office where going to jail is actually their goal. Works for me.
Tl;dr: my rule-consequentialist ethics don't have a problem with "liberalism, except where Nazi paraphernalia and holocaust denial", since those modifications have clearly demonstrated their worth and limited character.
You are seriously suggesting that "nobody else" is ever going to attempt what the Nazis did, ever? We've got billions of years until the sun makes Earth uninhabitable. History clearly shows us these things are cyclical. Also, your point about symbols is wrong, they are constantly looking for new dogwhistles and using them.
It seems like you're either lost in the weeds or have some obtuse agenda. This 'intellectual' sophistry is meaningless to 99% of your fellow humans. I don't see how anything you've said negates the paradox of tolerance-- there is a line to be drawn or fascists win, it's that simple to me and I cannot imagine an argument that would convince me otherwise.
However, I also think to a first approximation, virtue ethics has better consequentialist outcomes than naive consequentialist ethics does.
So I don't have an answer to the PoT; I just don't think it's a slam-dunk argument against tolerance at all. I espouse tolerance first and foremost for the sake of its ideal, and I hold that ideal because I prefer its generalized outcomes.
In other words, I can't help but notice that the Paradox of Tolerance is largely used as a tool to justify plain intolerance.