I expect that the Rust emitted by a hypothetical future WUFFS transpiler would be much easier to just drop into an existing Rust project than some C via a C FFI

I expect that the Rust emitted by a hypothetical future WUFFS transpiler would be much easier to just drop into an existing Rust project than some C via a C FFI. It's common for C libraries that do get wrapped today (e.g. openssl) to have a two phase wrapping, a -sys crate which turns the C into Rust C FFI and then another crate to turn the Rust C FFI into something actually palatable to ordinary people.