To really be censorship resistant you have to follow the example of the pirate streaming services. Have servers in multiple places. Multiple domain names. Be resilient to any instance going down.

Any capability the server has to violate user privacy a government has. So ensure you have as few capabilities as possible to violate privacy. If your users are very vulnerable make sure that you don’t have the data to expose them ever.

You can consider hosting in a “safe country” That’s just the beginning. You could make your service available on tor via hidden service address. That way even if users don’t have good operational security themselves you try to protect them from leaking their activity to whoever their vulnerable to

Iceland

Switzerland, Iceland, Finland, Spain, Egypt,Sweden, and some 3rd world countries that don’t really give a shit (though they might give a shit if your country makes them give a shit)