I'm basically trying to avoid situations where I might be legally obligated to prove a negative, that I did not take ideas or code from a proprietary yet source-available project that is topically very adjacent to some projects I work on. I write with Rust, use Rowan and tree-sitter crates, create LSP implementation, and so on.

I don't have a retained lawyer or legal budget, so it's just risk aversion on my part to treat this project as radioactive and never once look inside. Same reason a lot of folks don't look at GPL'd things.