That's a nice flowery and poetic concept of free speech, but it wasn't the reason the 1st amendment was made, that was made so that people running for office couldn't silent their opposition and the people could voice their criticisms without fear of retaliation from the government.

But whatever, fine, I'll humour you.

If you want to uphold your version of free speech, then don't give people like fascists (and terfs, which are just fascists with a fake mustache on at this point) a platform. They will actively work to dismantle that free speech, and thus are antithetical to it. No amount of trying to counter their arguments with facts and logic or appealing to their emotions will do anything in a public forum, history has shown that only private intervention has any chance of success at deradicalizing people on an individual basis. If you let the movement gain more visibility and legitimacy by entertaining their views on your platform, then you are helping them destroy free speech, full-stop. They are the true enemies of free society, and if you actually care about it you have to protect it from bad faith actors taking advantage of and manipulating it to erode the rights of others.

In a free society nobody is obligated to give anyone a platform or to entertain insanity. I work to uphold all civilization, not just western, by telling nazis to fuck off. You wouldn't let a guy flinging his own shit around to get up on stage, and that's the equivalent of what nazis are, except they actively spread propaganda and recruit other shit flingers, which is a lot easier to do up on a stage where everyone can see them flinging shit, and their shit can reach a lot more people. If you let them in, eventually all that will be left is a bunch of people flinging their shit around, and everyone else will have either left to avoid getting hit, or will have already been covered in it and are now suffering because of that. And it will all be because you wanted to defend to the death that guy's right to throw shit at people.

And then in the end your "free speech" is nothing but a feces covered nightmare, and the mob of poop tossers moves on to the next stage, their numbers greater than ever. Congratulations.