"I know better than you but I'm not going to bother to say why because it's an echo chamber" has strong "I have much much better arguments than you but they go to a different school so you wouldn't know them" vibes!
The thing is, for someone who claims not to be ignorant about gender critical feminism your earlier post certainly did a good impression of it! Pro tip - if you want to show why someone is wrong, it helps to be accurate about what they actually say and think, otherwise it just makes you look like you don't understand. (Unless of course the aim is not to actually address gender critical beliefs but simply to smear those who hold them. But I'm sure that is not the case here.)
The good thing about FWR is that unlike the actual echo chambers on FB, Bluesky, Reddit, Mastodon and various forums where gender critical comments are deleted and members who make them banned, on FWR opposing views are publicly challenged not simply disappeared.
The best way to break the FWR "echo chamber" is to argue effectively for an opposing position. I would listen and engage in good faith. I genuinely find it very frustrating that the pro gender posters who visit FWR make a worse case for genderism than I could, and I don't even believe in it!