Is there any jurisdiction where Nitter instances could be hosted while inconvenient Cease and Desist letters were... let's put it this way, rendered useless?

There's an instance served over TOR, I'm not sure if it's up, but that's a convenient way to render C&D letters useless

https://github.com/zedeus/nitter/wiki/Instances#tor

If piracy sites are a good indicator of locales that let you hide from American lawyers, then probably Russia

nitter.rdrama.net is still up