Maybe the NetzDG which is a German law that requires some unconstitutional comments (after being reported) to be hidden in Germany? This was and is highly controversial and applies to all social media.
Basically, I think they should go a step further: you only have access to EU-siloed twitter accounts without actively opting in and being warned.
My general read is that most Europeans would be okay with that (and would not opt-in), and the ones that wouldn't would just use a VPN anyway, so it wouldn't matter
Just because Europeans subscribe to a different notion of freedom of speech that doesn't mean that people want siloed and separated social media (except natural language barriers which do that automatically for most). Some probably want a "family friendly" internet but that's not unique to Europe.
Speaking from (my) German perspective it's important to realize that the national trauma of the Nazi and (Eastern German) Communist/Socialist regimes is embedded deeply into the foundations of society (e.g. even most far right extremist pay lip service to not be associated with the OG Nazis). A vast majority of people agree that the wish for society to not fall under one of those regimes again outweighs the freedom of individuals to advocate for violent far right/left causes and the abolishment of democracy.
A similar (though much weaker and more controversial) sentiment exists when it comes to celebrating crimes again humanity.
Anything beyond that is highly controversial and was/is a topic of many debates and political fights.
i mean the point here is not to argue which vision of free speech is correct, as an American i obviously disagree but what's at issue is how they're separated. y'all may not want a "siloed" solution, but y'all have also passed laws that restrict stuff more than the rest of the world. the rest of the world is not willing to have its speech policed to meet german/EU sensibilities so this is a possible compromise.