Yup, that's what I meant, but like you said, it doesn't carry the exact same meaning if I wrote it like that

Best way to address this is to reword a bit:

I probably would not use avoid using an instance that wasn't federated to Threads

Using "not" twice in a single sentence is generally something worth avoiding IMO.

I understood the meaning. I was clarifying the point OP was trying to make because I 100% disagree with it as worded.