I don't think you're actually grappling with the idea of "a cultural principle of free speech" here.
If I imagine a culture with the maximum level of respect for free speech as a principle - a strong cultural belief that the best way to reach the truth is by debating ideas, even terrible ones - I imagine a culture in which a Nazi can state their piece at a bar, and then everyone calmly discusses their opinions and why they're wrong.
If I imagine a culture with a minimum level of respect for free speech, I imagine a culture in which I might say something anodyne, like "the minimum wage should be increased," and lose all the friends who disagree with me.
Think, for example, about high school debate. In the past, it was an arena in which various controversial proposals were thrown out and discussed. It had a high level of respect for free speech as a principle.
Nowadays, some debate judges say things like (this is an actual quote):
> I will no longer evaluate and thus never vote for rightest capitalist-imperialist positions/arguments... Examples of arguments of this nature are as follows: fascism good, capitalism good, imperialist war good, neoliberalism good, defenses of US or otherwise bourgeois nationalism, Zionism or normalizing Israel, colonialism good, US white fascist policing good, etc.
Everyone here is exercising their freedom of speech. That doesn't mean they're showing equal respect for the free expression of ideas.