I used these Tweets because it's much more convenient than linking to his original work, which hardly anyone will make the effort to go through to confirm these things. Feel free to go and check these things out in his very own documents.

I'm willing to take the random twitter users word that Dr Zenz cited RFA four times in his paper. The issue is that the random twitter user doesn't provide proof, or even an argument, that this is a bad thing. Using RFA four times in what is clearly a long list of sources isn't an over-reliance on a single source, and the RFA is a reliable source, with both the New York Times and the Economist praising them for their work in Xinjiang.

You're conveniently letting out how that 8% to 80% "Typo" is not just in his tweet, but his original research. And also how that "Typo" got quoted entirely unchallenged by the likes of WaPo, Al Jazeera, Foreign Policy, and many others.

Was it? The other random twitter user you linked didn't mention this. Perhaps you should have used a better source?

That is slightly more embarrassing for Dr Zenz than if it was just in the twitter post, but embarrassing is all it is. The point he was making still stands, and all the duplication of the error suggests is that he was copying or transcribing from his research.