In the past Lemmy also had some hard-coded censorship. One could also say "it got deleted for now"

ocr-ing every image post to figure out if it’s from a chan board

Configurable by admin. Choose an instance that does not do this

auto-hiding anything tagged with “meme”

If I understand correctly what you mean, this is also configurable by instance admins. Choose an instance that does not do this

adding a hidden second layer of “trustworthiness” scoring to every user independent of the score of their posts and comments which pushes them up or down the comment chain, and pushing/pulling those trustworthiness scores from a server periodically

From what I've seen, in general in order to get below the threshold that blocks something one really has to work for it. And I haven't noticed the score affecting where comments are placed. Also, one can choose to have comments sorted by time

As for vote quota - choose an instance that set it impossibly high

In exchange on Piefed there are

• feeds. Private and shared (with federation)
  You can gather all communities you want to be in your private "cats" feed and those will be there, regardless if it makes sense or not. It's feed curated by you. Or you can follow someone's public feed and rely on their curation
• better notifications. You can turn them on for feeds, people, posts, comments...
• rolling together comments from posts about the same link
• I'm fuzzy on the details but some time ago I've heard that the personal blocking works better on Piefed. IIRC once you block an instance/account you won't be seeing it
• following microblogging accounts
• adding tags to your posts, so those get visible on microblogging fediverse too

I get that some of Rimu's decisions or reactions might have risen some eyebrows. But I moved to Piefed because of it's features and those have been threadiverse-changers for me