I'm sat behind a CGNAT for my home internet, so I can't really forward ports in. Tailscale has been great as a free thing to let me get a quick-and-easy VPN set up so I can remote into my network reliably.
I'm not signing up for Threads, but looking at some of the stuff other people show me coming out of there, it might end up just being yet-another-nazi-instance when they open up federation so might just end up getting blocked on those terms and not so much the "being meta/facebook" terms.
It's Zalgo
I think it's worth reading Proton's response on this and also worth noting Proton recently won Swiss court ruling (as in they paid for the lawyers and brought the case up et al.) that should help make it so proton isn't legally obligated by the Swiss government to do such things again.
You can also avoid what happened here by using the TOR endpoint Proton provides to login to their services.