Most nitter instances don't do anything to avoid legal trouble from X. They simply hope that X will not go after them. There are some instances which do put in effort to stay anonymous, and they usually do that with a Cloudflare tunnel to hide their server IP and by not posting any personal details online.
For Reddit you can use Redlib (https://github.com/redlib-org/redlib), I host an instance at https://redlib.miningtcup.me/ and people also like https://safereddit.com/.